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.Maps$13 implements com.google.common.base.Function<java.util.Map$Entry<K, V1>, java.util.Map$Entry<K, V2>>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.collect.Maps$13
  super_class: java.lang.Object
{
  private final com.google.common.collect.Maps$EntryTransformer val$transformer;
    descriptor: Lcom/google/common/collect/Maps$EntryTransformer;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  void <init>(com.google.common.collect.Maps$EntryTransformer);
    descriptor: (Lcom/google/common/collect/Maps$EntryTransformer;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.Maps$13 this
         0: .line 2000
            aload 0 /* this */
            aload 1
            putfield com.google.common.collect.Maps$13.val$transformer:Lcom/google/common/collect/Maps$EntryTransformer;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // com.google.common.collect.Maps$13 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Maps$13;
    MethodParameters:
                 Name  Flags
      val$transformer  final

  public java.util.Map$Entry<K, V2> apply(java.util.Map$Entry<K, V1>);
    descriptor: (Ljava/util/Map$Entry;)Ljava/util/Map$Entry;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.Maps$13 this
        start local 1 // java.util.Map$Entry entry
         0: .line 2003
            aload 0 /* this */
            getfield com.google.common.collect.Maps$13.val$transformer:Lcom/google/common/collect/Maps$EntryTransformer;
            aload 1 /* entry */
            invokestatic com.google.common.collect.Maps.transformEntry:(Lcom/google/common/collect/Maps$EntryTransformer;Ljava/util/Map$Entry;)Ljava/util/Map$Entry;
            areturn
        end local 1 // java.util.Map$Entry entry
        end local 0 // com.google.common.collect.Maps$13 this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    1     0   this  Lcom/google/common/collect/Maps$13;
            0    1     1  entry  Ljava/util/Map$Entry<TK;TV1;>;
    Signature: (Ljava/util/Map$Entry<TK;TV1;>;)Ljava/util/Map$Entry<TK;TV2;>;
    MethodParameters:
       Name  Flags
      entry  final

  public java.lang.Object apply(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: .line 1
            aload 0
            aload 1
            checkcast java.util.Map$Entry
            invokevirtual com.google.common.collect.Maps$13.apply:(Ljava/util/Map$Entry;)Ljava/util/Map$Entry;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Lcom/google/common/base/Function<Ljava/util/Map$Entry<TK;TV1;>;Ljava/util/Map$Entry<TK;TV2;>;>;
SourceFile: "Maps.java"
EnclosingMethod: com.google.common.collect.Maps.asEntryToEntryFunction:(Lcom/google/common/collect/Maps$EntryTransformer;)Lcom/google/common/base/Function;
NestHost: com.google.common.collect.Maps
InnerClasses:
  com.google.common.collect.Maps$13
  public abstract EntryTransformer = com.google.common.collect.Maps$EntryTransformer of com.google.common.collect.Maps
  public abstract Entry = java.util.Map$Entry of java.util.Map