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.NaturalOrdering extends com.google.common.collect.Ordering<java.lang.Comparable> implements java.io.Serializable
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.google.common.collect.NaturalOrdering
  super_class: com.google.common.collect.Ordering
{
  static final com.google.common.collect.NaturalOrdering INSTANCE;
    descriptor: Lcom/google/common/collect/NaturalOrdering;
    flags: (0x0018) ACC_STATIC, ACC_FINAL

  private transient com.google.common.collect.Ordering<java.lang.Comparable> nullsFirst;
    descriptor: Lcom/google/common/collect/Ordering;
    flags: (0x0082) ACC_PRIVATE, ACC_TRANSIENT
    Signature: Lcom/google/common/collect/Ordering<Ljava/lang/Comparable;>;
    RuntimeVisibleTypeAnnotations: 
      FIELD
        org.checkerframework.checker.nullness.qual.MonotonicNonNull()

  private transient com.google.common.collect.Ordering<java.lang.Comparable> nullsLast;
    descriptor: Lcom/google/common/collect/Ordering;
    flags: (0x0082) ACC_PRIVATE, ACC_TRANSIENT
    Signature: Lcom/google/common/collect/Ordering<Ljava/lang/Comparable;>;
    RuntimeVisibleTypeAnnotations: 
      FIELD
        org.checkerframework.checker.nullness.qual.MonotonicNonNull()

  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 0

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 29
            new com.google.common.collect.NaturalOrdering
            dup
            invokespecial com.google.common.collect.NaturalOrdering.<init>:()V
            putstatic com.google.common.collect.NaturalOrdering.INSTANCE:Lcom/google/common/collect/NaturalOrdering;
         1: .line 76
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public int compare(java.lang.Comparable, java.lang.Comparable);
    descriptor: (Ljava/lang/Comparable;Ljava/lang/Comparable;)I
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.google.common.collect.NaturalOrdering this
        start local 1 // java.lang.Comparable left
        start local 2 // java.lang.Comparable right
         0: .line 36
            aload 1 /* left */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 37
            aload 2 /* right */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         2: .line 38
            aload 1 /* left */
            aload 2 /* right */
            invokeinterface java.lang.Comparable.compareTo:(Ljava/lang/Object;)I
            ireturn
        end local 2 // java.lang.Comparable right
        end local 1 // java.lang.Comparable left
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    3     0   this  Lcom/google/common/collect/NaturalOrdering;
            0    3     1   left  Ljava/lang/Comparable;
            0    3     2  right  Ljava/lang/Comparable;
    MethodParameters:
       Name  Flags
      left   
      right  

  public <S extends java.lang.Comparable> com.google.common.collect.Ordering<S> nullsFirst();
    descriptor: ()Lcom/google/common/collect/Ordering;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=1
        start local 0 // com.google.common.collect.NaturalOrdering this
         0: .line 43
            aload 0 /* this */
            getfield com.google.common.collect.NaturalOrdering.nullsFirst:Lcom/google/common/collect/Ordering;
            astore 1 /* result */
        start local 1 // com.google.common.collect.Ordering result
         1: .line 44
            aload 1 /* result */
            ifnonnull 3
         2: .line 45
            aload 0 /* this */
            aload 0 /* this */
            invokespecial com.google.common.collect.Ordering.nullsFirst:()Lcom/google/common/collect/Ordering;
            dup_x1
            putfield com.google.common.collect.NaturalOrdering.nullsFirst:Lcom/google/common/collect/Ordering;
            astore 1 /* result */
         3: .line 47
      StackMap locals: com.google.common.collect.Ordering
      StackMap stack:
            aload 1 /* result */
            areturn
        end local 1 // com.google.common.collect.Ordering result
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    4     0    this  Lcom/google/common/collect/NaturalOrdering;
            1    4     1  result  Lcom/google/common/collect/Ordering<Ljava/lang/Comparable;>;
    Signature: <S::Ljava/lang/Comparable;>()Lcom/google/common/collect/Ordering<TS;>;

  public <S extends java.lang.Comparable> com.google.common.collect.Ordering<S> nullsLast();
    descriptor: ()Lcom/google/common/collect/Ordering;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=1
        start local 0 // com.google.common.collect.NaturalOrdering this
         0: .line 52
            aload 0 /* this */
            getfield com.google.common.collect.NaturalOrdering.nullsLast:Lcom/google/common/collect/Ordering;
            astore 1 /* result */
        start local 1 // com.google.common.collect.Ordering result
         1: .line 53
            aload 1 /* result */
            ifnonnull 3
         2: .line 54
            aload 0 /* this */
            aload 0 /* this */
            invokespecial com.google.common.collect.Ordering.nullsLast:()Lcom/google/common/collect/Ordering;
            dup_x1
            putfield com.google.common.collect.NaturalOrdering.nullsLast:Lcom/google/common/collect/Ordering;
            astore 1 /* result */
         3: .line 56
      StackMap locals: com.google.common.collect.Ordering
      StackMap stack:
            aload 1 /* result */
            areturn
        end local 1 // com.google.common.collect.Ordering result
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    4     0    this  Lcom/google/common/collect/NaturalOrdering;
            1    4     1  result  Lcom/google/common/collect/Ordering<Ljava/lang/Comparable;>;
    Signature: <S::Ljava/lang/Comparable;>()Lcom/google/common/collect/Ordering<TS;>;

  public <S extends java.lang.Comparable> com.google.common.collect.Ordering<S> reverse();
    descriptor: ()Lcom/google/common/collect/Ordering;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.NaturalOrdering this
         0: .line 61
            getstatic com.google.common.collect.ReverseNaturalOrdering.INSTANCE:Lcom/google/common/collect/ReverseNaturalOrdering;
            areturn
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/NaturalOrdering;
    Signature: <S::Ljava/lang/Comparable;>()Lcom/google/common/collect/Ordering<TS;>;

  private java.lang.Object readResolve();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.NaturalOrdering this
         0: .line 66
            getstatic com.google.common.collect.NaturalOrdering.INSTANCE:Lcom/google/common/collect/NaturalOrdering;
            areturn
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/NaturalOrdering;

  public java.lang.String toString();
    descriptor: ()Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.NaturalOrdering this
         0: .line 71
            ldc "Ordering.natural()"
            areturn
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/NaturalOrdering;

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.NaturalOrdering this
         0: .line 74
            aload 0 /* this */
            invokespecial com.google.common.collect.Ordering.<init>:()V
            return
        end local 0 // com.google.common.collect.NaturalOrdering this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/NaturalOrdering;

  public int compare(java.lang.Object, java.lang.Object);
    descriptor: (Ljava/lang/Object;Ljava/lang/Object;)I
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=3, locals=3, args_size=3
         0: .line 1
            aload 0
            aload 1
            checkcast java.lang.Comparable
            aload 2
            checkcast java.lang.Comparable
            invokevirtual com.google.common.collect.NaturalOrdering.compare:(Ljava/lang/Comparable;Ljava/lang/Comparable;)I
            ireturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Lcom/google/common/collect/Ordering<Ljava/lang/Comparable;>;Ljava/io/Serializable;
SourceFile: "NaturalOrdering.java"
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.GwtCompatible(serializable = true)