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. 
public class com.google.common.collect.ImmutableRangeSet$Builder<C extends java.lang.Comparable<?>>
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: com.google.common.collect.ImmutableRangeSet$Builder
  super_class: java.lang.Object
{
  private final java.util.List<com.google.common.collect.Range<C>> ranges;
    descriptor: Ljava/util/List;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/List<Lcom/google/common/collect/Range<TC;>;>;

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
         0: .line 721
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 722
            aload 0 /* this */
            invokestatic com.google.common.collect.Lists.newArrayList:()Ljava/util/ArrayList;
            putfield com.google.common.collect.ImmutableRangeSet$Builder.ranges:Ljava/util/List;
         2: .line 723
            return
        end local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;

  public com.google.common.collect.ImmutableRangeSet$Builder<C> add(com.google.common.collect.Range<C>);
    descriptor: (Lcom/google/common/collect/Range;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
        start local 1 // com.google.common.collect.Range range
         0: .line 735
            aload 1 /* range */
            invokevirtual com.google.common.collect.Range.isEmpty:()Z
            ifeq 1
            iconst_0
            goto 2
      StackMap locals:
      StackMap stack:
         1: iconst_1
      StackMap locals:
      StackMap stack: int
         2: ldc "range must not be empty, but was %s"
            aload 1 /* range */
            invokestatic com.google.common.base.Preconditions.checkArgument:(ZLjava/lang/String;Ljava/lang/Object;)V
         3: .line 736
            aload 0 /* this */
            getfield com.google.common.collect.ImmutableRangeSet$Builder.ranges:Ljava/util/List;
            aload 1 /* range */
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
         4: .line 737
            aload 0 /* this */
            areturn
        end local 1 // com.google.common.collect.Range range
        end local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    5     0   this  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
            0    5     1  range  Lcom/google/common/collect/Range<TC;>;
    Signature: (Lcom/google/common/collect/Range<TC;>;)Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
    RuntimeInvisibleAnnotations: 
      com.google.errorprone.annotations.CanIgnoreReturnValue()
    MethodParameters:
       Name  Flags
      range  

  public com.google.common.collect.ImmutableRangeSet$Builder<C> addAll(com.google.common.collect.RangeSet<C>);
    descriptor: (Lcom/google/common/collect/RangeSet;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
        start local 1 // com.google.common.collect.RangeSet ranges
         0: .line 747
            aload 0 /* this */
            aload 1 /* ranges */
            invokeinterface com.google.common.collect.RangeSet.asRanges:()Ljava/util/Set;
            invokevirtual com.google.common.collect.ImmutableRangeSet$Builder.addAll:(Ljava/lang/Iterable;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
            areturn
        end local 1 // com.google.common.collect.RangeSet ranges
        end local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    1     0    this  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
            0    1     1  ranges  Lcom/google/common/collect/RangeSet<TC;>;
    Signature: (Lcom/google/common/collect/RangeSet<TC;>;)Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
    RuntimeInvisibleAnnotations: 
      com.google.errorprone.annotations.CanIgnoreReturnValue()
    MethodParameters:
        Name  Flags
      ranges  

  public com.google.common.collect.ImmutableRangeSet$Builder<C> addAll(java.lang.Iterable<com.google.common.collect.Range<C>>);
    descriptor: (Ljava/lang/Iterable;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=2
        start local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
        start local 1 // java.lang.Iterable ranges
         0: .line 759
            aload 1 /* ranges */
            invokeinterface java.lang.Iterable.iterator:()Ljava/util/Iterator;
            astore 3
            goto 3
      StackMap locals: com.google.common.collect.ImmutableRangeSet$Builder java.lang.Iterable top java.util.Iterator
      StackMap stack:
         1: aload 3
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast com.google.common.collect.Range
            astore 2 /* range */
        start local 2 // com.google.common.collect.Range range
         2: .line 760
            aload 0 /* this */
            aload 2 /* range */
            invokevirtual com.google.common.collect.ImmutableRangeSet$Builder.add:(Lcom/google/common/collect/Range;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
            pop
        end local 2 // com.google.common.collect.Range range
         3: .line 759
      StackMap locals:
      StackMap stack:
            aload 3
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 1
         4: .line 762
            aload 0 /* this */
            areturn
        end local 1 // java.lang.Iterable ranges
        end local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    5     0    this  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
            0    5     1  ranges  Ljava/lang/Iterable<Lcom/google/common/collect/Range<TC;>;>;
            2    3     2   range  Lcom/google/common/collect/Range<TC;>;
    Signature: (Ljava/lang/Iterable<Lcom/google/common/collect/Range<TC;>;>;)Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
    RuntimeInvisibleAnnotations: 
      com.google.errorprone.annotations.CanIgnoreReturnValue()
    MethodParameters:
        Name  Flags
      ranges  

  com.google.common.collect.ImmutableRangeSet$Builder<C> combine(com.google.common.collect.ImmutableRangeSet$Builder<C>);
    descriptor: (Lcom/google/common/collect/ImmutableRangeSet$Builder;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
        start local 1 // com.google.common.collect.ImmutableRangeSet$Builder builder
         0: .line 767
            aload 0 /* this */
            aload 1 /* builder */
            getfield com.google.common.collect.ImmutableRangeSet$Builder.ranges:Ljava/util/List;
            invokevirtual com.google.common.collect.ImmutableRangeSet$Builder.addAll:(Ljava/lang/Iterable;)Lcom/google/common/collect/ImmutableRangeSet$Builder;
            pop
         1: .line 768
            aload 0 /* this */
            areturn
        end local 1 // com.google.common.collect.ImmutableRangeSet$Builder builder
        end local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    2     0     this  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
            0    2     1  builder  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
    Signature: (Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;)Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
    RuntimeInvisibleAnnotations: 
      com.google.errorprone.annotations.CanIgnoreReturnValue()
    MethodParameters:
         Name  Flags
      builder  

  public com.google.common.collect.ImmutableRangeSet<C> build();
    descriptor: ()Lcom/google/common/collect/ImmutableRangeSet;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=5, args_size=1
        start local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
         0: .line 778
            new com.google.common.collect.ImmutableList$Builder
            dup
            aload 0 /* this */
            getfield com.google.common.collect.ImmutableRangeSet$Builder.ranges:Ljava/util/List;
            invokeinterface java.util.List.size:()I
            invokespecial com.google.common.collect.ImmutableList$Builder.<init>:(I)V
         1: .line 777
            astore 1 /* mergedRangesBuilder */
        start local 1 // com.google.common.collect.ImmutableList$Builder mergedRangesBuilder
         2: .line 779
            aload 0 /* this */
            getfield com.google.common.collect.ImmutableRangeSet$Builder.ranges:Ljava/util/List;
            invokestatic com.google.common.collect.Range.rangeLexOrdering:()Lcom/google/common/collect/Ordering;
            invokestatic java.util.Collections.sort:(Ljava/util/List;Ljava/util/Comparator;)V
         3: .line 780
            aload 0 /* this */
            getfield com.google.common.collect.ImmutableRangeSet$Builder.ranges:Ljava/util/List;
            invokeinterface java.util.List.iterator:()Ljava/util/Iterator;
            invokestatic com.google.common.collect.Iterators.peekingIterator:(Ljava/util/Iterator;)Lcom/google/common/collect/PeekingIterator;
            astore 2 /* peekingItr */
        start local 2 // com.google.common.collect.PeekingIterator peekingItr
         4: .line 781
            goto 17
         5: .line 782
      StackMap locals: com.google.common.collect.ImmutableList$Builder com.google.common.collect.PeekingIterator
      StackMap stack:
            aload 2 /* peekingItr */
            invokeinterface com.google.common.collect.PeekingIterator.next:()Ljava/lang/Object;
            checkcast com.google.common.collect.Range
            astore 3 /* range */
        start local 3 // com.google.common.collect.Range range
         6: .line 783
            goto 15
         7: .line 784
      StackMap locals: com.google.common.collect.Range
      StackMap stack:
            aload 2 /* peekingItr */
            invokeinterface com.google.common.collect.PeekingIterator.peek:()Ljava/lang/Object;
            checkcast com.google.common.collect.Range
            astore 4 /* nextRange */
        start local 4 // com.google.common.collect.Range nextRange
         8: .line 785
            aload 3 /* range */
            aload 4 /* nextRange */
            invokevirtual com.google.common.collect.Range.isConnected:(Lcom/google/common/collect/Range;)Z
            ifeq 16
         9: .line 787
            aload 3 /* range */
            aload 4 /* nextRange */
            invokevirtual com.google.common.collect.Range.intersection:(Lcom/google/common/collect/Range;)Lcom/google/common/collect/Range;
            invokevirtual com.google.common.collect.Range.isEmpty:()Z
        10: .line 788
            ldc "Overlapping ranges not permitted but found %s overlapping %s"
        11: .line 789
            aload 3 /* range */
        12: .line 790
            aload 4 /* nextRange */
        13: .line 786
            invokestatic com.google.common.base.Preconditions.checkArgument:(ZLjava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
        14: .line 791
            aload 3 /* range */
            aload 2 /* peekingItr */
            invokeinterface com.google.common.collect.PeekingIterator.next:()Ljava/lang/Object;
            checkcast com.google.common.collect.Range
            invokevirtual com.google.common.collect.Range.span:(Lcom/google/common/collect/Range;)Lcom/google/common/collect/Range;
            astore 3 /* range */
        end local 4 // com.google.common.collect.Range nextRange
        15: .line 783
      StackMap locals:
      StackMap stack:
            aload 2 /* peekingItr */
            invokeinterface com.google.common.collect.PeekingIterator.hasNext:()Z
            ifne 7
        16: .line 796
      StackMap locals:
      StackMap stack:
            aload 1 /* mergedRangesBuilder */
            aload 3 /* range */
            invokevirtual com.google.common.collect.ImmutableList$Builder.add:(Ljava/lang/Object;)Lcom/google/common/collect/ImmutableList$Builder;
            pop
        end local 3 // com.google.common.collect.Range range
        17: .line 781
      StackMap locals:
      StackMap stack:
            aload 2 /* peekingItr */
            invokeinterface com.google.common.collect.PeekingIterator.hasNext:()Z
            ifne 5
        18: .line 798
            aload 1 /* mergedRangesBuilder */
            invokevirtual com.google.common.collect.ImmutableList$Builder.build:()Lcom/google/common/collect/ImmutableList;
            astore 3 /* mergedRanges */
        start local 3 // com.google.common.collect.ImmutableList mergedRanges
        19: .line 799
            aload 3 /* mergedRanges */
            invokevirtual com.google.common.collect.ImmutableList.isEmpty:()Z
            ifeq 21
        20: .line 800
            invokestatic com.google.common.collect.ImmutableRangeSet.of:()Lcom/google/common/collect/ImmutableRangeSet;
            areturn
        21: .line 801
      StackMap locals: com.google.common.collect.ImmutableList
      StackMap stack:
            aload 3 /* mergedRanges */
            invokevirtual com.google.common.collect.ImmutableList.size:()I
            iconst_1
            if_icmpne 24
        22: .line 802
            aload 3 /* mergedRanges */
            invokestatic com.google.common.collect.Iterables.getOnlyElement:(Ljava/lang/Iterable;)Ljava/lang/Object;
            checkcast com.google.common.collect.Range
            invokestatic com.google.common.collect.Range.all:()Lcom/google/common/collect/Range;
            invokevirtual com.google.common.collect.Range.equals:(Ljava/lang/Object;)Z
            ifeq 24
        23: .line 803
            invokestatic com.google.common.collect.ImmutableRangeSet.all:()Lcom/google/common/collect/ImmutableRangeSet;
            areturn
        24: .line 805
      StackMap locals:
      StackMap stack:
            new com.google.common.collect.ImmutableRangeSet
            dup
            aload 3 /* mergedRanges */
            invokespecial com.google.common.collect.ImmutableRangeSet.<init>:(Lcom/google/common/collect/ImmutableList;)V
            areturn
        end local 3 // com.google.common.collect.ImmutableList mergedRanges
        end local 2 // com.google.common.collect.PeekingIterator peekingItr
        end local 1 // com.google.common.collect.ImmutableList$Builder mergedRangesBuilder
        end local 0 // com.google.common.collect.ImmutableRangeSet$Builder this
      LocalVariableTable:
        Start  End  Slot                 Name  Signature
            0   25     0                 this  Lcom/google/common/collect/ImmutableRangeSet$Builder<TC;>;
            2   25     1  mergedRangesBuilder  Lcom/google/common/collect/ImmutableList$Builder<Lcom/google/common/collect/Range<TC;>;>;
            4   25     2           peekingItr  Lcom/google/common/collect/PeekingIterator<Lcom/google/common/collect/Range<TC;>;>;
            6   17     3                range  Lcom/google/common/collect/Range<TC;>;
            8   15     4            nextRange  Lcom/google/common/collect/Range<TC;>;
           19   25     3         mergedRanges  Lcom/google/common/collect/ImmutableList<Lcom/google/common/collect/Range<TC;>;>;
    Signature: ()Lcom/google/common/collect/ImmutableRangeSet<TC;>;
}
Signature: <C::Ljava/lang/Comparable<*>;>Ljava/lang/Object;
SourceFile: "ImmutableRangeSet.java"
NestHost: com.google.common.collect.ImmutableRangeSet
InnerClasses:
  public final Builder = com.google.common.collect.ImmutableList$Builder of com.google.common.collect.ImmutableList
  public Builder = com.google.common.collect.ImmutableRangeSet$Builder of com.google.common.collect.ImmutableRangeSet