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.Sets$FilteredSet<E> extends com.google.common.collect.Collections2$FilteredCollection<E> implements java.util.Set<E>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.collect.Sets$FilteredSet
  super_class: com.google.common.collect.Collections2$FilteredCollection
{
  void <init>(java.util.Set<E>, com.google.common.base.Predicate<? super E>);
    descriptor: (Ljava/util/Set;Lcom/google/common/base/Predicate;)V
    flags: (0x0000) 
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // com.google.common.collect.Sets$FilteredSet this
        start local 1 // java.util.Set unfiltered
        start local 2 // com.google.common.base.Predicate predicate
         0: .line 1138
            aload 0 /* this */
            aload 1 /* unfiltered */
            aload 2 /* predicate */
            invokespecial com.google.common.collect.Collections2$FilteredCollection.<init>:(Ljava/util/Collection;Lcom/google/common/base/Predicate;)V
         1: .line 1139
            return
        end local 2 // com.google.common.base.Predicate predicate
        end local 1 // java.util.Set unfiltered
        end local 0 // com.google.common.collect.Sets$FilteredSet this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    2     0        this  Lcom/google/common/collect/Sets$FilteredSet<TE;>;
            0    2     1  unfiltered  Ljava/util/Set<TE;>;
            0    2     2   predicate  Lcom/google/common/base/Predicate<-TE;>;
    Signature: (Ljava/util/Set<TE;>;Lcom/google/common/base/Predicate<-TE;>;)V
    MethodParameters:
            Name  Flags
      unfiltered  
      predicate   

  public boolean equals(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.Sets$FilteredSet this
        start local 1 // java.lang.Object object
         0: .line 1143
            aload 0 /* this */
            aload 1 /* object */
            invokestatic com.google.common.collect.Sets.equalsImpl:(Ljava/util/Set;Ljava/lang/Object;)Z
            ireturn
        end local 1 // java.lang.Object object
        end local 0 // com.google.common.collect.Sets$FilteredSet this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    1     0    this  Lcom/google/common/collect/Sets$FilteredSet<TE;>;
            0    1     1  object  Ljava/lang/Object;
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
        Name  Flags
      object  

  public int hashCode();
    descriptor: ()I
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.Sets$FilteredSet this
         0: .line 1148
            aload 0 /* this */
            invokestatic com.google.common.collect.Sets.hashCodeImpl:(Ljava/util/Set;)I
            ireturn
        end local 0 // com.google.common.collect.Sets$FilteredSet this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Sets$FilteredSet<TE;>;
}
Signature: <E:Ljava/lang/Object;>Lcom/google/common/collect/Collections2$FilteredCollection<TE;>;Ljava/util/Set<TE;>;
SourceFile: "Sets.java"
NestHost: com.google.common.collect.Sets
InnerClasses:
  FilteredCollection = com.google.common.collect.Collections2$FilteredCollection of com.google.common.collect.Collections2
  private FilteredSet = com.google.common.collect.Sets$FilteredSet of com.google.common.collect.Sets