https://projects.spring.io/spring-data-jpa: Spring Data module for JPA repositories. (Pivotal Software, Inc.) 
public class org.springframework.data.jpa.util.JpaMetamodel
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.springframework.data.jpa.util.JpaMetamodel
  super_class: java.lang.Object
{
  private static final java.util.Map<javax.persistence.metamodel.Metamodel, org.springframework.data.jpa.util.JpaMetamodel> CACHE;
    descriptor: Ljava/util/Map;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    Signature: Ljava/util/Map<Ljavax/persistence/metamodel/Metamodel;Lorg/springframework/data/jpa/util/JpaMetamodel;>;

  private final javax.persistence.metamodel.Metamodel metamodel;
    descriptor: Ljavax/persistence/metamodel/Metamodel;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private org.springframework.data.util.Lazy<java.util.Collection<java.lang.Class<?>>> managedTypes;
    descriptor: Lorg/springframework/data/util/Lazy;
    flags: (0x0002) ACC_PRIVATE
    Signature: Lorg/springframework/data/util/Lazy<Ljava/util/Collection<Ljava/lang/Class<*>;>;>;

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=3, locals=0, args_size=0
         0: .line 41
            new java.util.concurrent.ConcurrentHashMap
            dup
            iconst_4
            invokespecial java.util.concurrent.ConcurrentHashMap.<init>:(I)V
            putstatic org.springframework.data.jpa.util.JpaMetamodel.CACHE:Ljava/util/Map;
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  private void <init>(javax.persistence.metamodel.Metamodel);
    descriptor: (Ljavax/persistence/metamodel/Metamodel;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.springframework.data.jpa.util.JpaMetamodel this
        start local 1 // javax.persistence.metamodel.Metamodel metamodel
         0: .line 52
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 54
            aload 1 /* metamodel */
            ldc "Metamodel must not be null!"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         2: .line 56
            aload 0 /* this */
            aload 1 /* metamodel */
            putfield org.springframework.data.jpa.util.JpaMetamodel.metamodel:Ljavax/persistence/metamodel/Metamodel;
         3: .line 57
            aload 0 /* this */
            aload 1 /* metamodel */
            invokedynamic get(Ljavax/persistence/metamodel/Metamodel;)Ljava/util/function/Supplier;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  ()Ljava/lang/Object;
                  org/springframework/data/jpa/util/JpaMetamodel.lambda$0(Ljavax/persistence/metamodel/Metamodel;)Ljava/util/Collection; (6)
                  ()Ljava/util/Collection;
            invokestatic org.springframework.data.util.Lazy.of:(Ljava/util/function/Supplier;)Lorg/springframework/data/util/Lazy;
            putfield org.springframework.data.jpa.util.JpaMetamodel.managedTypes:Lorg/springframework/data/util/Lazy;
         4: .line 61
            return
        end local 1 // javax.persistence.metamodel.Metamodel metamodel
        end local 0 // org.springframework.data.jpa.util.JpaMetamodel this
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    5     0       this  Lorg/springframework/data/jpa/util/JpaMetamodel;
            0    5     1  metamodel  Ljavax/persistence/metamodel/Metamodel;
    MethodParameters:
           Name  Flags
      metamodel  

  public static org.springframework.data.jpa.util.JpaMetamodel of(javax.persistence.metamodel.Metamodel);
    descriptor: (Ljavax/persistence/metamodel/Metamodel;)Lorg/springframework/data/jpa/util/JpaMetamodel;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // javax.persistence.metamodel.Metamodel metamodel
         0: .line 64
            getstatic org.springframework.data.jpa.util.JpaMetamodel.CACHE:Ljava/util/Map;
            aload 0 /* metamodel */
            invokedynamic apply()Ljava/util/function/Function;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Ljava/lang/Object;
                  org/springframework/data/jpa/util/JpaMetamodel.<init>(Ljavax/persistence/metamodel/Metamodel;)V (8)
                  (Ljavax/persistence/metamodel/Metamodel;)Lorg/springframework/data/jpa/util/JpaMetamodel;
            invokeinterface java.util.Map.computeIfAbsent:(Ljava/lang/Object;Ljava/util/function/Function;)Ljava/lang/Object;
            checkcast org.springframework.data.jpa.util.JpaMetamodel
            areturn
        end local 0 // javax.persistence.metamodel.Metamodel metamodel
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    1     0  metamodel  Ljavax/persistence/metamodel/Metamodel;
    MethodParameters:
           Name  Flags
      metamodel  

  public boolean isJpaManaged(java.lang.Class<?>);
    descriptor: (Ljava/lang/Class;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.springframework.data.jpa.util.JpaMetamodel this
        start local 1 // java.lang.Class type
         0: .line 75
            aload 1 /* type */
            ldc "Type must not be null!"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         1: .line 77
            aload 0 /* this */
            getfield org.springframework.data.jpa.util.JpaMetamodel.managedTypes:Lorg/springframework/data/util/Lazy;
            invokevirtual org.springframework.data.util.Lazy.get:()Ljava/lang/Object;
            checkcast java.util.Collection
            aload 1 /* type */
            invokeinterface java.util.Collection.contains:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // java.lang.Class type
        end local 0 // org.springframework.data.jpa.util.JpaMetamodel this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/springframework/data/jpa/util/JpaMetamodel;
            0    2     1  type  Ljava/lang/Class<*>;
    Signature: (Ljava/lang/Class<*>;)Z
    MethodParameters:
      Name  Flags
      type  

  public boolean isSingleIdAttribute(java.lang.Class<?>, java.lang.String, java.lang.Class<?>);
    descriptor: (Ljava/lang/Class;Ljava/lang/String;Ljava/lang/Class;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=4
        start local 0 // org.springframework.data.jpa.util.JpaMetamodel this
        start local 1 // java.lang.Class entity
        start local 2 // java.lang.String name
        start local 3 // java.lang.Class attributeType
         0: .line 90
            aload 0 /* this */
            getfield org.springframework.data.jpa.util.JpaMetamodel.metamodel:Ljavax/persistence/metamodel/Metamodel;
            invokeinterface javax.persistence.metamodel.Metamodel.getEntities:()Ljava/util/Set;
            invokeinterface java.util.Set.stream:()Ljava/util/stream/Stream;
         1: .line 91
            aload 1 /* entity */
            invokedynamic test(Ljava/lang/Class;)Ljava/util/function/Predicate;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Z
                  org/springframework/data/jpa/util/JpaMetamodel.lambda$4(Ljava/lang/Class;Ljavax/persistence/metamodel/EntityType;)Z (6)
                  (Ljavax/persistence/metamodel/EntityType;)Z
            invokeinterface java.util.stream.Stream.filter:(Ljava/util/function/Predicate;)Ljava/util/stream/Stream;
         2: .line 92
            invokeinterface java.util.stream.Stream.findFirst:()Ljava/util/Optional;
         3: .line 93
            invokedynamic apply()Ljava/util/function/Function;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Ljava/lang/Object;
                  org/springframework/data/jpa/util/JpaMetamodel.lambda$5(Ljavax/persistence/metamodel/EntityType;)Ljava/util/Optional; (6)
                  (Ljavax/persistence/metamodel/EntityType;)Ljava/util/Optional;
            invokevirtual java.util.Optional.flatMap:(Ljava/util/function/Function;)Ljava/util/Optional;
         4: .line 94
            aload 3 /* attributeType */
            invokedynamic test(Ljava/lang/Class;)Ljava/util/function/Predicate;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Z
                  org/springframework/data/jpa/util/JpaMetamodel.lambda$6(Ljava/lang/Class;Ljavax/persistence/metamodel/SingularAttribute;)Z (6)
                  (Ljavax/persistence/metamodel/SingularAttribute;)Z
            invokevirtual java.util.Optional.filter:(Ljava/util/function/Predicate;)Ljava/util/Optional;
         5: .line 95
            aload 2 /* name */
            invokedynamic apply(Ljava/lang/String;)Ljava/util/function/Function;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Ljava/lang/Object;
                  org/springframework/data/jpa/util/JpaMetamodel.lambda$7(Ljava/lang/String;Ljavax/persistence/metamodel/SingularAttribute;)Ljava/lang/Boolean; (6)
                  (Ljavax/persistence/metamodel/SingularAttribute;)Ljava/lang/Boolean;
            invokevirtual java.util.Optional.map:(Ljava/util/function/Function;)Ljava/util/Optional;
         6: .line 96
            iconst_0
            invokestatic java.lang.Boolean.valueOf:(Z)Ljava/lang/Boolean;
            invokevirtual java.util.Optional.orElse:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.lang.Boolean
            invokevirtual java.lang.Boolean.booleanValue:()Z
         7: .line 90
            ireturn
        end local 3 // java.lang.Class attributeType
        end local 2 // java.lang.String name
        end local 1 // java.lang.Class entity
        end local 0 // org.springframework.data.jpa.util.JpaMetamodel this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    8     0           this  Lorg/springframework/data/jpa/util/JpaMetamodel;
            0    8     1         entity  Ljava/lang/Class<*>;
            0    8     2           name  Ljava/lang/String;
            0    8     3  attributeType  Ljava/lang/Class<*>;
    Signature: (Ljava/lang/Class<*>;Ljava/lang/String;Ljava/lang/Class<*>;)Z
    MethodParameters:
               Name  Flags
      entity         
      name           
      attributeType  

  static void clear();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=1, locals=0, args_size=0
         0: .line 103
            getstatic org.springframework.data.jpa.util.JpaMetamodel.CACHE:Ljava/util/Map;
            invokeinterface java.util.Map.clear:()V
         1: .line 104
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  private static java.util.Optional<? extends javax.persistence.metamodel.SingularAttribute<?, ?>> getSingularIdAttribute(javax.persistence.metamodel.EntityType<?>);
    descriptor: (Ljavax/persistence/metamodel/EntityType;)Ljava/util/Optional;
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // javax.persistence.metamodel.EntityType entityType
         0: .line 115
            aload 0 /* entityType */
            invokeinterface javax.persistence.metamodel.EntityType.hasSingleIdAttribute:()Z
            ifne 2
         1: .line 116
            invokestatic java.util.Optional.empty:()Ljava/util/Optional;
            areturn
         2: .line 119
      StackMap locals:
      StackMap stack:
            aload 0 /* entityType */
            invokeinterface javax.persistence.metamodel.EntityType.getSingularAttributes:()Ljava/util/Set;
            invokeinterface java.util.Set.stream:()Ljava/util/stream/Stream;
         3: .line 120
            invokedynamic test()Ljava/util/function/Predicate;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Z
                  javax/persistence/metamodel/SingularAttribute.isId()Z (9 itf)
                  (Ljavax/persistence/metamodel/SingularAttribute;)Z
            invokeinterface java.util.stream.Stream.filter:(Ljava/util/function/Predicate;)Ljava/util/stream/Stream;
         4: .line 121
            invokeinterface java.util.stream.Stream.findFirst:()Ljava/util/Optional;
         5: .line 119
            areturn
        end local 0 // javax.persistence.metamodel.EntityType entityType
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    6     0  entityType  Ljavax/persistence/metamodel/EntityType<*>;
    Signature: (Ljavax/persistence/metamodel/EntityType<*>;)Ljava/util/Optional<+Ljavax/persistence/metamodel/SingularAttribute<**>;>;
    MethodParameters:
            Name  Flags
      entityType  

  private static java.util.Collection lambda$0(javax.persistence.metamodel.Metamodel);
    descriptor: (Ljavax/persistence/metamodel/Metamodel;)Ljava/util/Collection;
    flags: (0x100a) ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=2, locals=1, args_size=1
         0: .line 57
            aload 0
            invokeinterface javax.persistence.metamodel.Metamodel.getManagedTypes:()Ljava/util/Set;
            invokeinterface java.util.Set.stream:()Ljava/util/stream/Stream;
         1: .line 58
            invokedynamic apply()Ljava/util/function/Function;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Ljava/lang/Object;
                  javax/persistence/metamodel/Type.getJavaType()Ljava/lang/Class; (9 itf)
                  (Ljavax/persistence/metamodel/ManagedType;)Ljava/lang/Class;
            invokeinterface java.util.stream.Stream.map:(Ljava/util/function/Function;)Ljava/util/stream/Stream;
         2: .line 59
            invokedynamic test()Ljava/util/function/Predicate;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Z
                  org/springframework/data/jpa/util/JpaMetamodel.lambda$2(Ljava/lang/Class;)Z (6)
                  (Ljava/lang/Class;)Z
            invokeinterface java.util.stream.Stream.filter:(Ljava/util/function/Predicate;)Ljava/util/stream/Stream;
         3: .line 60
            invokestatic org.springframework.data.util.StreamUtils.toUnmodifiableSet:()Ljava/util/stream/Collector;
            invokeinterface java.util.stream.Stream.collect:(Ljava/util/stream/Collector;)Ljava/lang/Object;
            checkcast java.util.Collection
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  private static boolean lambda$4(java.lang.Class, javax.persistence.metamodel.EntityType);
    descriptor: (Ljava/lang/Class;Ljavax/persistence/metamodel/EntityType;)Z
    flags: (0x100a) ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
        start local 1 // javax.persistence.metamodel.EntityType it
         0: .line 91
            aload 0
            aload 1 /* it */
            invokeinterface javax.persistence.metamodel.EntityType.getJavaType:()Ljava/lang/Class;
            invokevirtual java.lang.Object.equals:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // javax.persistence.metamodel.EntityType it
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     1    it  Ljavax/persistence/metamodel/EntityType<*>;

  private static java.util.Optional lambda$5(javax.persistence.metamodel.EntityType);
    descriptor: (Ljavax/persistence/metamodel/EntityType;)Ljava/util/Optional;
    flags: (0x100a) ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // javax.persistence.metamodel.EntityType it
         0: .line 93
            aload 0 /* it */
            invokestatic org.springframework.data.jpa.util.JpaMetamodel.getSingularIdAttribute:(Ljavax/persistence/metamodel/EntityType;)Ljava/util/Optional;
            areturn
        end local 0 // javax.persistence.metamodel.EntityType it
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0    it  Ljavax/persistence/metamodel/EntityType<*>;

  private static boolean lambda$6(java.lang.Class, javax.persistence.metamodel.SingularAttribute);
    descriptor: (Ljava/lang/Class;Ljavax/persistence/metamodel/SingularAttribute;)Z
    flags: (0x100a) ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
        start local 1 // javax.persistence.metamodel.SingularAttribute it
         0: .line 94
            aload 1 /* it */
            invokeinterface javax.persistence.metamodel.SingularAttribute.getJavaType:()Ljava/lang/Class;
            aload 0
            invokevirtual java.lang.Object.equals:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // javax.persistence.metamodel.SingularAttribute it
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     1    it  Ljavax/persistence/metamodel/SingularAttribute<TX;TT;>;

  private static java.lang.Boolean lambda$7(java.lang.String, javax.persistence.metamodel.SingularAttribute);
    descriptor: (Ljava/lang/String;Ljavax/persistence/metamodel/SingularAttribute;)Ljava/lang/Boolean;
    flags: (0x100a) ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
        start local 1 // javax.persistence.metamodel.SingularAttribute it
         0: .line 95
            aload 1 /* it */
            invokeinterface javax.persistence.metamodel.SingularAttribute.getName:()Ljava/lang/String;
            aload 0
            invokevirtual java.lang.String.equals:(Ljava/lang/Object;)Z
            invokestatic java.lang.Boolean.valueOf:(Z)Ljava/lang/Boolean;
            areturn
        end local 1 // javax.persistence.metamodel.SingularAttribute it
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     1    it  Ljavax/persistence/metamodel/SingularAttribute<TX;TT;>;

  private static boolean lambda$2(java.lang.Class);
    descriptor: (Ljava/lang/Class;)Z
    flags: (0x100a) ACC_PRIVATE, ACC_STATIC, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.lang.Class it
         0: .line 59
            aload 0 /* it */
            ifnull 1
            iconst_1
            goto 2
      StackMap locals:
      StackMap stack:
         1: iconst_0
      StackMap locals:
      StackMap stack: int
         2: ireturn
        end local 0 // java.lang.Class it
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0    it  Ljava/lang/Class<Ljava/lang/Object;>;
}
SourceFile: "JpaMetamodel.java"
InnerClasses:
  public final Lookup = java.lang.invoke.MethodHandles$Lookup of java.lang.invoke.MethodHandles