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.AppendableWriter extends java.io.Writer
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.io.AppendableWriter
  super_class: java.io.Writer
{
  private final java.lang.Appendable target;
    descriptor: Ljava/lang/Appendable;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private boolean closed;
    descriptor: Z
    flags: (0x0002) ACC_PRIVATE

  void <init>(java.lang.Appendable);
    descriptor: (Ljava/lang/Appendable;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // java.lang.Appendable target
         0: .line 44
            aload 0 /* this */
            invokespecial java.io.Writer.<init>:()V
         1: .line 45
            aload 0 /* this */
            aload 1 /* target */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.lang.Appendable
            putfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
         2: .line 46
            return
        end local 1 // java.lang.Appendable target
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    3     0    this  Lcom/google/common/io/AppendableWriter;
            0    3     1  target  Ljava/lang/Appendable;
    MethodParameters:
        Name  Flags
      target  

  public void write(char[], int, int);
    descriptor: ([CII)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=6, locals=4, args_size=4
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // char[] cbuf
        start local 2 // int off
        start local 3 // int len
         0: .line 54
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 57
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            new java.lang.String
            dup
            aload 1 /* cbuf */
            iload 2 /* off */
            iload 3 /* len */
            invokespecial java.lang.String.<init>:([CII)V
            invokeinterface java.lang.Appendable.append:(Ljava/lang/CharSequence;)Ljava/lang/Appendable;
            pop
         2: .line 58
            return
        end local 3 // int len
        end local 2 // int off
        end local 1 // char[] cbuf
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/io/AppendableWriter;
            0    3     1  cbuf  [C
            0    3     2   off  I
            0    3     3   len  I
    Exceptions:
      throws java.io.IOException
    MethodParameters:
      Name  Flags
      cbuf  
      off   
      len   

  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.AppendableWriter this
        start local 1 // int c
         0: .line 66
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 67
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            iload 1 /* c */
            i2c
            invokeinterface java.lang.Appendable.append:(C)Ljava/lang/Appendable;
            pop
         2: .line 68
            return
        end local 1 // int c
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/io/AppendableWriter;
            0    3     1     c  I
    Exceptions:
      throws java.io.IOException
    MethodParameters:
      Name  Flags
      c     

  public void write(java.lang.String);
    descriptor: (Ljava/lang/String;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // java.lang.String str
         0: .line 72
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 73
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            aload 1 /* str */
            invokeinterface java.lang.Appendable.append:(Ljava/lang/CharSequence;)Ljava/lang/Appendable;
            pop
         2: .line 74
            return
        end local 1 // java.lang.String str
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/io/AppendableWriter;
            0    3     1   str  Ljava/lang/String;
    Exceptions:
      throws java.io.IOException
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
      Name  Flags
      str   

  public void write(java.lang.String, int, int);
    descriptor: (Ljava/lang/String;II)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=4, args_size=4
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // java.lang.String str
        start local 2 // int off
        start local 3 // int len
         0: .line 78
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 80
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            aload 1 /* str */
            iload 2 /* off */
            iload 2 /* off */
            iload 3 /* len */
            iadd
            invokeinterface java.lang.Appendable.append:(Ljava/lang/CharSequence;II)Ljava/lang/Appendable;
            pop
         2: .line 81
            return
        end local 3 // int len
        end local 2 // int off
        end local 1 // java.lang.String str
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/io/AppendableWriter;
            0    3     1   str  Ljava/lang/String;
            0    3     2   off  I
            0    3     3   len  I
    Exceptions:
      throws java.io.IOException
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
      Name  Flags
      str   
      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.AppendableWriter this
         0: .line 85
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 86
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            instanceof java.io.Flushable
            ifeq 3
         2: .line 87
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            checkcast java.io.Flushable
            invokeinterface java.io.Flushable.flush:()V
         3: .line 89
      StackMap locals:
      StackMap stack:
            return
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lcom/google/common/io/AppendableWriter;
    Exceptions:
      throws java.io.IOException

  public void close();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.common.io.AppendableWriter this
         0: .line 93
            aload 0 /* this */
            iconst_1
            putfield com.google.common.io.AppendableWriter.closed:Z
         1: .line 94
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            instanceof java.io.Closeable
            ifeq 3
         2: .line 95
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            checkcast java.io.Closeable
            invokeinterface java.io.Closeable.close:()V
         3: .line 97
      StackMap locals:
      StackMap stack:
            return
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lcom/google/common/io/AppendableWriter;
    Exceptions:
      throws java.io.IOException

  public java.io.Writer append(char);
    descriptor: (C)Ljava/io/Writer;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // char c
         0: .line 101
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 102
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            iload 1 /* c */
            invokeinterface java.lang.Appendable.append:(C)Ljava/lang/Appendable;
            pop
         2: .line 103
            aload 0 /* this */
            areturn
        end local 1 // char c
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/io/AppendableWriter;
            0    3     1     c  C
    Exceptions:
      throws java.io.IOException
    MethodParameters:
      Name  Flags
      c     

  public java.io.Writer append(java.lang.CharSequence);
    descriptor: (Ljava/lang/CharSequence;)Ljava/io/Writer;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // java.lang.CharSequence charSeq
         0: .line 108
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 109
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            aload 1 /* charSeq */
            invokeinterface java.lang.Appendable.append:(Ljava/lang/CharSequence;)Ljava/lang/Appendable;
            pop
         2: .line 110
            aload 0 /* this */
            areturn
        end local 1 // java.lang.CharSequence charSeq
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    3     0     this  Lcom/google/common/io/AppendableWriter;
            0    3     1  charSeq  Ljava/lang/CharSequence;
    Exceptions:
      throws java.io.IOException
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
         Name  Flags
      charSeq  

  public java.io.Writer append(java.lang.CharSequence, int, int);
    descriptor: (Ljava/lang/CharSequence;II)Ljava/io/Writer;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=4, args_size=4
        start local 0 // com.google.common.io.AppendableWriter this
        start local 1 // java.lang.CharSequence charSeq
        start local 2 // int start
        start local 3 // int end
         0: .line 115
            aload 0 /* this */
            invokevirtual com.google.common.io.AppendableWriter.checkNotClosed:()V
         1: .line 116
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.target:Ljava/lang/Appendable;
            aload 1 /* charSeq */
            iload 2 /* start */
            iload 3 /* end */
            invokeinterface java.lang.Appendable.append:(Ljava/lang/CharSequence;II)Ljava/lang/Appendable;
            pop
         2: .line 117
            aload 0 /* this */
            areturn
        end local 3 // int end
        end local 2 // int start
        end local 1 // java.lang.CharSequence charSeq
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    3     0     this  Lcom/google/common/io/AppendableWriter;
            0    3     1  charSeq  Ljava/lang/CharSequence;
            0    3     2    start  I
            0    3     3      end  I
    Exceptions:
      throws java.io.IOException
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
         Name  Flags
      charSeq  
      start    
      end      

  private void checkNotClosed();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.google.common.io.AppendableWriter this
         0: .line 121
            aload 0 /* this */
            getfield com.google.common.io.AppendableWriter.closed:Z
            ifeq 2
         1: .line 122
            new java.io.IOException
            dup
            ldc "Cannot write to a closed writer."
            invokespecial java.io.IOException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 124
      StackMap locals:
      StackMap stack:
            return
        end local 0 // com.google.common.io.AppendableWriter this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/io/AppendableWriter;
    Exceptions:
      throws java.io.IOException

  public java.lang.Appendable append(java.lang.CharSequence, int, int);
    descriptor: (Ljava/lang/CharSequence;II)Ljava/lang/Appendable;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=4, locals=4, args_size=4
         0: .line 1
            aload 0
            aload 1
            iload 2
            iload 3
            invokevirtual com.google.common.io.AppendableWriter.append:(Ljava/lang/CharSequence;II)Ljava/io/Writer;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    Exceptions:
      throws java.io.IOException

  public java.lang.Appendable append(java.lang.CharSequence);
    descriptor: (Ljava/lang/CharSequence;)Ljava/lang/Appendable;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: .line 1
            aload 0
            aload 1
            invokevirtual com.google.common.io.AppendableWriter.append:(Ljava/lang/CharSequence;)Ljava/io/Writer;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    Exceptions:
      throws java.io.IOException

  public java.lang.Appendable append(char);
    descriptor: (C)Ljava/lang/Appendable;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: .line 1
            aload 0
            iload 1
            invokevirtual com.google.common.io.AppendableWriter.append:(C)Ljava/io/Writer;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    Exceptions:
      throws java.io.IOException
}
SourceFile: "AppendableWriter.java"
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.GwtIncompatible()