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.io.BaseEncoding$Base16Encoding extends com.google.common.io.BaseEncoding$StandardBaseEncoding
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.google.common.io.BaseEncoding$Base16Encoding
  super_class: com.google.common.io.BaseEncoding$StandardBaseEncoding
{
  final char[] encoding;
    descriptor: [C
    flags: (0x0010) ACC_FINAL

  void <init>(java.lang.String, java.lang.String);
    descriptor: (Ljava/lang/String;Ljava/lang/String;)V
    flags: (0x0000) 
    Code:
      stack=5, locals=3, args_size=3
        start local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
        start local 1 // java.lang.String name
        start local 2 // java.lang.String alphabetChars
         0: .line 874
            aload 0 /* this */
            new com.google.common.io.BaseEncoding$Alphabet
            dup
            aload 1 /* name */
            aload 2 /* alphabetChars */
            invokevirtual java.lang.String.toCharArray:()[C
            invokespecial com.google.common.io.BaseEncoding$Alphabet.<init>:(Ljava/lang/String;[C)V
            invokespecial com.google.common.io.BaseEncoding$Base16Encoding.<init>:(Lcom/google/common/io/BaseEncoding$Alphabet;)V
         1: .line 875
            return
        end local 2 // java.lang.String alphabetChars
        end local 1 // java.lang.String name
        end local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    2     0           this  Lcom/google/common/io/BaseEncoding$Base16Encoding;
            0    2     1           name  Ljava/lang/String;
            0    2     2  alphabetChars  Ljava/lang/String;
    MethodParameters:
               Name  Flags
      name           
      alphabetChars  

  private void <init>(com.google.common.io.BaseEncoding$Alphabet);
    descriptor: (Lcom/google/common/io/BaseEncoding$Alphabet;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=5, locals=3, args_size=2
        start local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
        start local 1 // com.google.common.io.BaseEncoding$Alphabet alphabet
         0: .line 878
            aload 0 /* this */
            aload 1 /* alphabet */
            aconst_null
            invokespecial com.google.common.io.BaseEncoding$StandardBaseEncoding.<init>:(Lcom/google/common/io/BaseEncoding$Alphabet;Ljava/lang/Character;)V
         1: .line 871
            aload 0 /* this */
            sipush 512
            newarray 5
            putfield com.google.common.io.BaseEncoding$Base16Encoding.encoding:[C
         2: .line 879
            aload 1 /* alphabet */
            getfield com.google.common.io.BaseEncoding$Alphabet.chars:[C
            arraylength
            bipush 16
            if_icmpne 3
            iconst_1
            goto 4
      StackMap locals: com.google.common.io.BaseEncoding$Base16Encoding com.google.common.io.BaseEncoding$Alphabet
      StackMap stack:
         3: iconst_0
      StackMap locals:
      StackMap stack: int
         4: invokestatic com.google.common.base.Preconditions.checkArgument:(Z)V
         5: .line 880
            iconst_0
            istore 2 /* i */
        start local 2 // int i
         6: goto 10
         7: .line 881
      StackMap locals: int
      StackMap stack:
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$Base16Encoding.encoding:[C
            iload 2 /* i */
            aload 1 /* alphabet */
            iload 2 /* i */
            iconst_4
            iushr
            invokevirtual com.google.common.io.BaseEncoding$Alphabet.encode:(I)C
            castore
         8: .line 882
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$Base16Encoding.encoding:[C
            iload 2 /* i */
            sipush 256
            ior
            aload 1 /* alphabet */
            iload 2 /* i */
            bipush 15
            iand
            invokevirtual com.google.common.io.BaseEncoding$Alphabet.encode:(I)C
            castore
         9: .line 880
            iinc 2 /* i */ 1
      StackMap locals:
      StackMap stack:
        10: iload 2 /* i */
            sipush 256
            if_icmplt 7
        end local 2 // int i
        11: .line 884
            return
        end local 1 // com.google.common.io.BaseEncoding$Alphabet alphabet
        end local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0   12     0      this  Lcom/google/common/io/BaseEncoding$Base16Encoding;
            0   12     1  alphabet  Lcom/google/common/io/BaseEncoding$Alphabet;
            6   11     2         i  I
    MethodParameters:
          Name  Flags
      alphabet  

  void encodeTo(java.lang.Appendable, byte[], int, int);
    descriptor: (Ljava/lang/Appendable;[BII)V
    flags: (0x0000) 
    Code:
      stack=4, locals=7, args_size=5
        start local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
        start local 1 // java.lang.Appendable target
        start local 2 // byte[] bytes
        start local 3 // int off
        start local 4 // int len
         0: .line 888
            aload 1 /* target */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 889
            iload 3 /* off */
            iload 3 /* off */
            iload 4 /* len */
            iadd
            aload 2 /* bytes */
            arraylength
            invokestatic com.google.common.base.Preconditions.checkPositionIndexes:(III)V
         2: .line 890
            iconst_0
            istore 5 /* i */
        start local 5 // int i
         3: goto 8
         4: .line 891
      StackMap locals: int
      StackMap stack:
            aload 2 /* bytes */
            iload 3 /* off */
            iload 5 /* i */
            iadd
            baload
            sipush 255
            iand
            istore 6 /* b */
        start local 6 // int b
         5: .line 892
            aload 1 /* target */
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$Base16Encoding.encoding:[C
            iload 6 /* b */
            caload
            invokeinterface java.lang.Appendable.append:(C)Ljava/lang/Appendable;
            pop
         6: .line 893
            aload 1 /* target */
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$Base16Encoding.encoding:[C
            iload 6 /* b */
            sipush 256
            ior
            caload
            invokeinterface java.lang.Appendable.append:(C)Ljava/lang/Appendable;
            pop
        end local 6 // int b
         7: .line 890
            iinc 5 /* i */ 1
      StackMap locals:
      StackMap stack:
         8: iload 5 /* i */
            iload 4 /* len */
            if_icmplt 4
        end local 5 // int i
         9: .line 895
            return
        end local 4 // int len
        end local 3 // int off
        end local 2 // byte[] bytes
        end local 1 // java.lang.Appendable target
        end local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   10     0    this  Lcom/google/common/io/BaseEncoding$Base16Encoding;
            0   10     1  target  Ljava/lang/Appendable;
            0   10     2   bytes  [B
            0   10     3     off  I
            0   10     4     len  I
            3    9     5       i  I
            5    7     6       b  I
    Exceptions:
      throws java.io.IOException
    MethodParameters:
        Name  Flags
      target  
      bytes   
      off     
      len     

  int decodeTo(byte[], java.lang.CharSequence);
    descriptor: ([BLjava/lang/CharSequence;)I
    flags: (0x0000) 
    Code:
      stack=5, locals=6, args_size=3
        start local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
        start local 1 // byte[] target
        start local 2 // java.lang.CharSequence chars
         0: .line 899
            aload 1 /* target */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 900
            aload 2 /* chars */
            invokeinterface java.lang.CharSequence.length:()I
            iconst_2
            irem
            iconst_1
            if_icmpne 3
         2: .line 901
            new com.google.common.io.BaseEncoding$DecodingException
            dup
            new java.lang.StringBuilder
            dup
            ldc "Invalid input length "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 2 /* chars */
            invokeinterface java.lang.CharSequence.length:()I
            invokevirtual java.lang.StringBuilder.append:(I)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            invokespecial com.google.common.io.BaseEncoding$DecodingException.<init>:(Ljava/lang/String;)V
            athrow
         3: .line 903
      StackMap locals:
      StackMap stack:
            iconst_0
            istore 3 /* bytesWritten */
        start local 3 // int bytesWritten
         4: .line 904
            iconst_0
            istore 4 /* i */
        start local 4 // int i
         5: goto 9
         6: .line 905
      StackMap locals: int int
      StackMap stack:
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$Base16Encoding.alphabet:Lcom/google/common/io/BaseEncoding$Alphabet;
            aload 2 /* chars */
            iload 4 /* i */
            invokeinterface java.lang.CharSequence.charAt:(I)C
            invokevirtual com.google.common.io.BaseEncoding$Alphabet.decode:(C)I
            iconst_4
            ishl
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$Base16Encoding.alphabet:Lcom/google/common/io/BaseEncoding$Alphabet;
            aload 2 /* chars */
            iload 4 /* i */
            iconst_1
            iadd
            invokeinterface java.lang.CharSequence.charAt:(I)C
            invokevirtual com.google.common.io.BaseEncoding$Alphabet.decode:(C)I
            ior
            istore 5 /* decoded */
        start local 5 // int decoded
         7: .line 906
            aload 1 /* target */
            iload 3 /* bytesWritten */
            iinc 3 /* bytesWritten */ 1
            iload 5 /* decoded */
            i2b
            bastore
        end local 5 // int decoded
         8: .line 904
            iinc 4 /* i */ 2
      StackMap locals:
      StackMap stack:
         9: iload 4 /* i */
            aload 2 /* chars */
            invokeinterface java.lang.CharSequence.length:()I
            if_icmplt 6
        end local 4 // int i
        10: .line 908
            iload 3 /* bytesWritten */
            ireturn
        end local 3 // int bytesWritten
        end local 2 // java.lang.CharSequence chars
        end local 1 // byte[] target
        end local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
      LocalVariableTable:
        Start  End  Slot          Name  Signature
            0   11     0          this  Lcom/google/common/io/BaseEncoding$Base16Encoding;
            0   11     1        target  [B
            0   11     2         chars  Ljava/lang/CharSequence;
            4   11     3  bytesWritten  I
            5   10     4             i  I
            7    8     5       decoded  I
    Exceptions:
      throws com.google.common.io.BaseEncoding$DecodingException
    MethodParameters:
        Name  Flags
      target  
      chars   

  com.google.common.io.BaseEncoding newInstance(com.google.common.io.BaseEncoding$Alphabet, java.lang.Character);
    descriptor: (Lcom/google/common/io/BaseEncoding$Alphabet;Ljava/lang/Character;)Lcom/google/common/io/BaseEncoding;
    flags: (0x0000) 
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
        start local 1 // com.google.common.io.BaseEncoding$Alphabet alphabet
        start local 2 // java.lang.Character paddingChar
         0: .line 913
            new com.google.common.io.BaseEncoding$Base16Encoding
            dup
            aload 1 /* alphabet */
            invokespecial com.google.common.io.BaseEncoding$Base16Encoding.<init>:(Lcom/google/common/io/BaseEncoding$Alphabet;)V
            areturn
        end local 2 // java.lang.Character paddingChar
        end local 1 // com.google.common.io.BaseEncoding$Alphabet alphabet
        end local 0 // com.google.common.io.BaseEncoding$Base16Encoding this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    1     0         this  Lcom/google/common/io/BaseEncoding$Base16Encoding;
            0    1     1     alphabet  Lcom/google/common/io/BaseEncoding$Alphabet;
            0    1     2  paddingChar  Ljava/lang/Character;
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
             Name  Flags
      alphabet     
      paddingChar  
}
SourceFile: "BaseEncoding.java"
NestHost: com.google.common.io.BaseEncoding
InnerClasses:
  private final Alphabet = com.google.common.io.BaseEncoding$Alphabet of com.google.common.io.BaseEncoding
  final Base16Encoding = com.google.common.io.BaseEncoding$Base16Encoding of com.google.common.io.BaseEncoding
  public final DecodingException = com.google.common.io.BaseEncoding$DecodingException of com.google.common.io.BaseEncoding
  StandardBaseEncoding = com.google.common.io.BaseEncoding$StandardBaseEncoding of com.google.common.io.BaseEncoding