<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def line_text(self, line_nbr):
 """ Gets the text of the specified line. :param line_nbr: The line number of the text to get :return: Entire line's text :rtype: str """

        doc = self._editor.document()
        block = doc.findBlockByNumber(line_nbr)
        return block.text()