https://github.com/google/guava/guava: Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more. 
class com.google.common.collect.Streams$1OptionalState
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.collect.Streams$1OptionalState
  super_class: java.lang.Object
{
  boolean set;
    descriptor: Z
    flags: (0x0000) 

  T value;
    descriptor: Ljava/lang/Object;
    flags: (0x0000) 
    Signature: TT;

  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.common.collect.Streams$1OptionalState this
         0: .line 822
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 823
            aload 0 /* this */
            iconst_0
            putfield com.google.common.collect.Streams$1OptionalState.set:Z
         2: .line 824
            aload 0 /* this */
            aconst_null
            putfield com.google.common.collect.Streams$1OptionalState.value:Ljava/lang/Object;
         3: .line 822
            return
        end local 0 // com.google.common.collect.Streams$1OptionalState this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lcom/google/common/collect/Streams$1OptionalState;

  void set();
    descriptor: (Ljava/lang/Object;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.Streams$1OptionalState this
        start local 1 // java.lang.Object value
         0: .line 827
            aload 0 /* this */
            iconst_1
            putfield com.google.common.collect.Streams$1OptionalState.set:Z
         1: .line 828
            aload 0 /* this */
            aload 1 /* value */
            putfield com.google.common.collect.Streams$1OptionalState.value:Ljava/lang/Object;
         2: .line 829
            return
        end local 1 // java.lang.Object value
        end local 0 // com.google.common.collect.Streams$1OptionalState this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    3     0   this  Lcom/google/common/collect/Streams$1OptionalState;
            0    3     1  value  TT;
    Signature: (TT;)V
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
       Name  Flags
      value  

  T get();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.Streams$1OptionalState this
         0: .line 832
            aload 0 /* this */
            getfield com.google.common.collect.Streams$1OptionalState.set:Z
            invokestatic com.google.common.base.Preconditions.checkState:(Z)V
         1: .line 833
            aload 0 /* this */
            getfield com.google.common.collect.Streams$1OptionalState.value:Ljava/lang/Object;
            areturn
        end local 0 // com.google.common.collect.Streams$1OptionalState this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/google/common/collect/Streams$1OptionalState;
    Signature: ()TT;
}
SourceFile: "Streams.java"
EnclosingMethod: com.google.common.collect.Streams.findLast:(Ljava/util/stream/Stream;)Ljava/util/Optional;
NestHost: com.google.common.collect.Streams
InnerClasses:
  OptionalState = com.google.common.collect.Streams$1OptionalState