code: @Override
    public NonBlockingStringWriter append (final CharSequence aCS)
    {
      if (aCS == null)
        write ("null");
      else
        write (aCS.toString ());
      return this;
    }
docs: Appends the specified character sequence to this writer.
  <p>
  An invocation of this method of the form <tt>out.append(csq)</tt> behaves in
  exactly the same way as the invocation
  
  <pre>
  out.write (csq.toString ())
  </pre>
  <p>
  Depending on the specification of <tt>toString</tt> for the character
  sequence <tt>csq</tt>, the entire sequence may not be appended. For instance,
  invoking the <tt>toString</tt> method of a character buffer will return a
  subsequence whose content depends upon the buffer's position and limit.
  
  @param aCS
  The character sequence to append. If <tt>csq</tt> is <tt>null</tt>,
  then the four characters <tt>"null"</tt> are appended to this writer.
  @return This writer