code: public void append(final byte[] data, final int start, final int len) {
  		final int oldLength = this.bytes.length;
  		setCapacity(this.bytes.length + len, true);
  		System.arraycopy(data, start, this.bytes, oldLength, len);
  	}
docs: Append a range of bytes to the end of the given data.
  
  @param data
  the data to copy from
  @param start
  the first position to append from data
  @param len
  the number of bytes to append