code: public void put(ByteArray source, int index, int length)
      {
          put(source.mBuffer.array(), index, length);
      }
docs: Add data at the current position.
  
  @param source
  Source data.
  
  @param index
  The index in the source data. Data from the index is copied.
  
  @param length
  The length of data to copy.