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.io.BaseEncoding$5 extends java.io.Writer
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.io.BaseEncoding$5
  super_class: java.io.Writer
{
  private final java.lang.Appendable val$seperatingAppendable;
    descriptor: Ljava/lang/Appendable;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  private final java.io.Writer val$delegate;
    descriptor: Ljava/io/Writer;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  void <init>(java.lang.Appendable, java.io.Writer);
    descriptor: (Ljava/lang/Appendable;Ljava/io/Writer;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.google.common.io.BaseEncoding$5 this
         0: .line 1036
            aload 0 /* this */
            aload 1
            putfield com.google.common.io.BaseEncoding$5.val$seperatingAppendable:Ljava/lang/Appendable;
            aload 0 /* this */
            aload 2
            putfield com.google.common.io.BaseEncoding$5.val$delegate:Ljava/io/Writer;
            aload 0 /* this */
            invokespecial java.io.Writer.<init>:()V
            return
        end local 0 // com.google.common.io.BaseEncoding$5 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/io/BaseEncoding$5;
    MethodParameters:
                          Name  Flags
      val$seperatingAppendable  final
      val$delegate              final

  public void write(int);
    descriptor: (I)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.io.BaseEncoding$5 this
        start local 1 // int c
         0: .line 1039
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$5.val$seperatingAppendable:Ljava/lang/Appendable;
            iload 1 /* c */
            i2c
            invokeinterface java.lang.Appendable.append:(C)Ljava/lang/Appendable;
            pop
         1: .line 1040
            return
        end local 1 // int c
        end local 0 // com.google.common.io.BaseEncoding$5 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/google/common/io/BaseEncoding$5;
            0    2     1     c  I
    Exceptions:
      throws java.io.IOException
    MethodParameters:
      Name  Flags
      c     

  public void write(char[], int, int);
    descriptor: ([CII)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=4
        start local 0 // com.google.common.io.BaseEncoding$5 this
        start local 1 // char[] chars
        start local 2 // int off
        start local 3 // int len
         0: .line 1044
            new java.lang.UnsupportedOperationException
            dup
            invokespecial java.lang.UnsupportedOperationException.<init>:()V
            athrow
        end local 3 // int len
        end local 2 // int off
        end local 1 // char[] chars
        end local 0 // com.google.common.io.BaseEncoding$5 this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    1     0   this  Lcom/google/common/io/BaseEncoding$5;
            0    1     1  chars  [C
            0    1     2    off  I
            0    1     3    len  I
    Exceptions:
      throws java.io.IOException
    MethodParameters:
       Name  Flags
      chars  
      off    
      len    

  public void flush();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.io.BaseEncoding$5 this
         0: .line 1049
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$5.val$delegate:Ljava/io/Writer;
            invokevirtual java.io.Writer.flush:()V
         1: .line 1050
            return
        end local 0 // com.google.common.io.BaseEncoding$5 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/google/common/io/BaseEncoding$5;
    Exceptions:
      throws java.io.IOException

  public void close();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.io.BaseEncoding$5 this
         0: .line 1054
            aload 0 /* this */
            getfield com.google.common.io.BaseEncoding$5.val$delegate:Ljava/io/Writer;
            invokevirtual java.io.Writer.close:()V
         1: .line 1055
            return
        end local 0 // com.google.common.io.BaseEncoding$5 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/google/common/io/BaseEncoding$5;
    Exceptions:
      throws java.io.IOException
}
SourceFile: "BaseEncoding.java"
EnclosingMethod: com.google.common.io.BaseEncoding.separatingWriter:(Ljava/io/Writer;Ljava/lang/String;I)Ljava/io/Writer;
NestHost: com.google.common.io.BaseEncoding
InnerClasses:
  com.google.common.io.BaseEncoding$5