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. 
final class com.google.common.collect.MultimapBuilder$TreeSetSupplier<V> implements com.google.common.base.Supplier<java.util.SortedSet<V>>, java.io.Serializable
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.google.common.collect.MultimapBuilder$TreeSetSupplier
  super_class: java.lang.Object
{
  private final java.util.Comparator<? super V> comparator;
    descriptor: Ljava/util/Comparator;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Comparator<-TV;>;

  void <init>(java.util.Comparator<? super V>);
    descriptor: (Ljava/util/Comparator;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.MultimapBuilder$TreeSetSupplier this
        start local 1 // java.util.Comparator comparator
         0: .line 243
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 244
            aload 0 /* this */
            aload 1 /* comparator */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.util.Comparator
            putfield com.google.common.collect.MultimapBuilder$TreeSetSupplier.comparator:Ljava/util/Comparator;
         2: .line 245
            return
        end local 1 // java.util.Comparator comparator
        end local 0 // com.google.common.collect.MultimapBuilder$TreeSetSupplier this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    3     0        this  Lcom/google/common/collect/MultimapBuilder$TreeSetSupplier<TV;>;
            0    3     1  comparator  Ljava/util/Comparator<-TV;>;
    Signature: (Ljava/util/Comparator<-TV;>;)V
    MethodParameters:
            Name  Flags
      comparator  

  public java.util.SortedSet<V> get();
    descriptor: ()Ljava/util/SortedSet;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.google.common.collect.MultimapBuilder$TreeSetSupplier this
         0: .line 249
            new java.util.TreeSet
            dup
            aload 0 /* this */
            getfield com.google.common.collect.MultimapBuilder$TreeSetSupplier.comparator:Ljava/util/Comparator;
            invokespecial java.util.TreeSet.<init>:(Ljava/util/Comparator;)V
            areturn
        end local 0 // com.google.common.collect.MultimapBuilder$TreeSetSupplier this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/MultimapBuilder$TreeSetSupplier<TV;>;
    Signature: ()Ljava/util/SortedSet<TV;>;

  public java.lang.Object get();
    descriptor: ()Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual com.google.common.collect.MultimapBuilder$TreeSetSupplier.get:()Ljava/util/SortedSet;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: <V:Ljava/lang/Object;>Ljava/lang/Object;Lcom/google/common/base/Supplier<Ljava/util/SortedSet<TV;>;>;Ljava/io/Serializable;
SourceFile: "MultimapBuilder.java"
NestHost: com.google.common.collect.MultimapBuilder
InnerClasses:
  private final TreeSetSupplier = com.google.common.collect.MultimapBuilder$TreeSetSupplier of com.google.common.collect.MultimapBuilder