https://spring.io/projects/spring-boot: Spring Boot Actuator (Pivotal Software, Inc.) 
public class org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry implements org.springframework.boot.actuate.health.HealthIndicatorRegistry
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry
  super_class: java.lang.Object
{
  private final java.lang.Object monitor;
    descriptor: Ljava/lang/Object;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final java.util.Map<java.lang.String, org.springframework.boot.actuate.health.HealthIndicator> healthIndicators;
    descriptor: Ljava/util/Map;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Map<Ljava/lang/String;Lorg/springframework/boot/actuate/health/HealthIndicator;>;

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
         0: .line 44
            aload 0 /* this */
            new java.util.LinkedHashMap
            dup
            invokespecial java.util.LinkedHashMap.<init>:()V
            invokespecial org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.<init>:(Ljava/util/Map;)V
         1: .line 45
            return
        end local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry;

  public void <init>(java.util.Map<java.lang.String, org.springframework.boot.actuate.health.HealthIndicator>);
    descriptor: (Ljava/util/Map;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
        start local 1 // java.util.Map healthIndicators
         0: .line 52
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 36
            aload 0 /* this */
            new java.lang.Object
            dup
            invokespecial java.lang.Object.<init>:()V
            putfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.monitor:Ljava/lang/Object;
         2: .line 53
            aload 1 /* healthIndicators */
            ldc "HealthIndicators must not be null"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         3: .line 54
            aload 0 /* this */
            new java.util.LinkedHashMap
            dup
            aload 1 /* healthIndicators */
            invokespecial java.util.LinkedHashMap.<init>:(Ljava/util/Map;)V
            putfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.healthIndicators:Ljava/util/Map;
         4: .line 55
            return
        end local 1 // java.util.Map healthIndicators
        end local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
      LocalVariableTable:
        Start  End  Slot              Name  Signature
            0    5     0              this  Lorg/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry;
            0    5     1  healthIndicators  Ljava/util/Map<Ljava/lang/String;Lorg/springframework/boot/actuate/health/HealthIndicator;>;
    Signature: (Ljava/util/Map<Ljava/lang/String;Lorg/springframework/boot/actuate/health/HealthIndicator;>;)V
    MethodParameters:
                  Name  Flags
      healthIndicators  

  public void register(java.lang.String, org.springframework.boot.actuate.health.HealthIndicator);
    descriptor: (Ljava/lang/String;Lorg/springframework/boot/actuate/health/HealthIndicator;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=5, args_size=3
        start local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
        start local 1 // java.lang.String name
        start local 2 // org.springframework.boot.actuate.health.HealthIndicator healthIndicator
         0: .line 59
            aload 2 /* healthIndicator */
            ldc "HealthIndicator must not be null"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         1: .line 60
            aload 1 /* name */
            ldc "Name must not be null"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         2: .line 61
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.monitor:Ljava/lang/Object;
            dup
            astore 3
            monitorenter
         3: .line 62
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.healthIndicators:Ljava/util/Map;
            aload 1 /* name */
            aload 2 /* healthIndicator */
            invokeinterface java.util.Map.putIfAbsent:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.springframework.boot.actuate.health.HealthIndicator
            astore 4 /* existing */
        start local 4 // org.springframework.boot.actuate.health.HealthIndicator existing
         4: .line 63
            aload 4 /* existing */
            ifnull 6
         5: .line 64
            new java.lang.IllegalStateException
            dup
            new java.lang.StringBuilder
            dup
            ldc "HealthIndicator with name '"
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 1 /* name */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            ldc "' already registered"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            invokespecial java.lang.IllegalStateException.<init>:(Ljava/lang/String;)V
            athrow
        end local 4 // org.springframework.boot.actuate.health.HealthIndicator existing
         6: .line 61
      StackMap locals: java.lang.Object
      StackMap stack:
            aload 3
            monitorexit
         7: goto 10
      StackMap locals:
      StackMap stack: java.lang.Throwable
         8: aload 3
            monitorexit
         9: athrow
        10: .line 67
      StackMap locals:
      StackMap stack:
            return
        end local 2 // org.springframework.boot.actuate.health.HealthIndicator healthIndicator
        end local 1 // java.lang.String name
        end local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0   11     0             this  Lorg/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry;
            0   11     1             name  Ljava/lang/String;
            0   11     2  healthIndicator  Lorg/springframework/boot/actuate/health/HealthIndicator;
            4    6     4         existing  Lorg/springframework/boot/actuate/health/HealthIndicator;
      Exception table:
        from    to  target  type
           3     7       8  any
           8     9       8  any
    MethodParameters:
                 Name  Flags
      name             
      healthIndicator  

  public org.springframework.boot.actuate.health.HealthIndicator unregister(java.lang.String);
    descriptor: (Ljava/lang/String;)Lorg/springframework/boot/actuate/health/HealthIndicator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=2
        start local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
        start local 1 // java.lang.String name
         0: .line 71
            aload 1 /* name */
            ldc "Name must not be null"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         1: .line 72
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.monitor:Ljava/lang/Object;
            dup
            astore 2
            monitorenter
         2: .line 73
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.healthIndicators:Ljava/util/Map;
            aload 1 /* name */
            invokeinterface java.util.Map.remove:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.springframework.boot.actuate.health.HealthIndicator
            aload 2
            monitorexit
         3: areturn
         4: .line 72
      StackMap locals: org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry java.lang.String java.lang.Object
      StackMap stack: java.lang.Throwable
            aload 2
            monitorexit
         5: athrow
        end local 1 // java.lang.String name
        end local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Lorg/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry;
            0    6     1  name  Ljava/lang/String;
      Exception table:
        from    to  target  type
           2     3       4  any
           4     5       4  any
    MethodParameters:
      Name  Flags
      name  

  public org.springframework.boot.actuate.health.HealthIndicator get(java.lang.String);
    descriptor: (Ljava/lang/String;)Lorg/springframework/boot/actuate/health/HealthIndicator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=2
        start local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
        start local 1 // java.lang.String name
         0: .line 79
            aload 1 /* name */
            ldc "Name must not be null"
            invokestatic org.springframework.util.Assert.notNull:(Ljava/lang/Object;Ljava/lang/String;)V
         1: .line 80
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.monitor:Ljava/lang/Object;
            dup
            astore 2
            monitorenter
         2: .line 81
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.healthIndicators:Ljava/util/Map;
            aload 1 /* name */
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.springframework.boot.actuate.health.HealthIndicator
            aload 2
            monitorexit
         3: areturn
         4: .line 80
      StackMap locals: org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry java.lang.String java.lang.Object
      StackMap stack: java.lang.Throwable
            aload 2
            monitorexit
         5: athrow
        end local 1 // java.lang.String name
        end local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Lorg/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry;
            0    6     1  name  Ljava/lang/String;
      Exception table:
        from    to  target  type
           2     3       4  any
           4     5       4  any
    MethodParameters:
      Name  Flags
      name  

  public java.util.Map<java.lang.String, org.springframework.boot.actuate.health.HealthIndicator> getAll();
    descriptor: ()Ljava/util/Map;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=1
        start local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
         0: .line 87
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.monitor:Ljava/lang/Object;
            dup
            astore 1
            monitorenter
         1: .line 88
            new java.util.LinkedHashMap
            dup
            aload 0 /* this */
            getfield org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry.healthIndicators:Ljava/util/Map;
            invokespecial java.util.LinkedHashMap.<init>:(Ljava/util/Map;)V
            invokestatic java.util.Collections.unmodifiableMap:(Ljava/util/Map;)Ljava/util/Map;
            aload 1
            monitorexit
         2: areturn
         3: .line 87
      StackMap locals: org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry java.lang.Object
      StackMap stack: java.lang.Throwable
            aload 1
            monitorexit
         4: athrow
        end local 0 // org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lorg/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry;
      Exception table:
        from    to  target  type
           1     2       3  any
           3     4       3  any
    Signature: ()Ljava/util/Map<Ljava/lang/String;Lorg/springframework/boot/actuate/health/HealthIndicator;>;
}
SourceFile: "DefaultHealthIndicatorRegistry.java"
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()