https://github.com/eclipse/eclipse-collections/eclipse-collections-api: Eclipse Collections is a collections framework for Java. It has JDK-compatible List, Set and Map implementations with a rich API and set of utility classes that work with any JDK compatible Collections, Arrays, Maps or Strings. The iteration protocol was inspired by the Smalltalk collection framework.
  • Craig P. Motlin
  • Donald Raab
  • Mohammad A. Rezaei
  • Hiroshi Ito
  • Nikhil J. Nanivadekar 
public final class org.eclipse.collections.api.factory.Sets
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.api.factory.Sets
  super_class: java.lang.Object
{
  public static final org.eclipse.collections.api.factory.set.ImmutableSetFactory immutable;
    descriptor: Lorg/eclipse/collections/api/factory/set/ImmutableSetFactory;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  public static final org.eclipse.collections.api.factory.set.MutableSetFactory mutable;
    descriptor: Lorg/eclipse/collections/api/factory/set/MutableSetFactory;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  public static final org.eclipse.collections.api.factory.set.FixedSizeSetFactory fixedSize;
    descriptor: Lorg/eclipse/collections/api/factory/set/FixedSizeSetFactory;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=1, locals=0, args_size=0
         0: .line 48
            ldc Lorg/eclipse/collections/api/factory/set/ImmutableSetFactory;
            invokestatic org.eclipse.collections.api.factory.ServiceLoaderUtils.loadServiceClass:(Ljava/lang/Class;)Ljava/lang/Object;
            checkcast org.eclipse.collections.api.factory.set.ImmutableSetFactory
         1: .line 47
            putstatic org.eclipse.collections.api.factory.Sets.immutable:Lorg/eclipse/collections/api/factory/set/ImmutableSetFactory;
         2: .line 50
            ldc Lorg/eclipse/collections/api/factory/set/MutableSetFactory;
            invokestatic org.eclipse.collections.api.factory.ServiceLoaderUtils.loadServiceClass:(Ljava/lang/Class;)Ljava/lang/Object;
            checkcast org.eclipse.collections.api.factory.set.MutableSetFactory
         3: .line 49
            putstatic org.eclipse.collections.api.factory.Sets.mutable:Lorg/eclipse/collections/api/factory/set/MutableSetFactory;
         4: .line 52
            ldc Lorg/eclipse/collections/api/factory/set/FixedSizeSetFactory;
            invokestatic org.eclipse.collections.api.factory.ServiceLoaderUtils.loadServiceClass:(Ljava/lang/Class;)Ljava/lang/Object;
            checkcast org.eclipse.collections.api.factory.set.FixedSizeSetFactory
         5: .line 51
            putstatic org.eclipse.collections.api.factory.Sets.fixedSize:Lorg/eclipse/collections/api/factory/set/FixedSizeSetFactory;
         6: .line 52
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.eclipse.collections.api.factory.Sets this
         0: .line 54
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 56
            new java.lang.AssertionError
            dup
            ldc "Suppress default constructor for noninstantiability"
            invokespecial java.lang.AssertionError.<init>:(Ljava/lang/Object;)V
            athrow
        end local 0 // org.eclipse.collections.api.factory.Sets this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/eclipse/collections/api/factory/Sets;
}
SourceFile: "Sets.java"