code: @Nonnull
    @ReturnsMutableCopy
    public byte [] toByteArray (@Nonnull final Charset aCharset)
    {
      return StringHelper.encodeCharToBytes (m_aBuf, 0, m_nCount, aCharset);
    }
docs: Returns a copy of the input data as bytes in the correct charset.
  
  @param aCharset
  The charset to be used. May not be <code>null</code>.
  @return an array of bytes. Never <code>null</code>.