code: public void writeTo (@Nonnull final byte [] aBuf, @Nonnegative final int nOfs, @Nonnegative final int nLen)
    {
      writeTo (aBuf, nOfs, nLen, true);
    }
docs: Write current content to the passed byte array. The copied elements are
  removed from this streams buffer.
  
  @param aBuf
  Byte array to write to. May not be <code>null</code>.
  @param nOfs
  Offset to start writing. Must be &ge; 0.
  @param nLen
  Number of bytes to copy. Must be &ge; 0.