code: public void newLineAtOffset (final float tx, final float ty) throws IOException
    {
      if (!inTextMode)
      {
        throw new IllegalStateException ("Error: must call beginText() before newLineAtOffset()");
      }
      writeOperand (tx);
      writeOperand (ty);
      writeOperator ((byte) 'T', (byte) 'd');
    }
docs: The Td operator. Move to the start of the next line, offset from the start
  of the current line by (tx, ty).
  
  @param tx
  The x translation.
  @param ty
  The y translation.
  @throws IOException
  If there is an error writing to the stream.
  @throws IllegalStateException
  If the method was not allowed to be called at this time.