Deletes the document lines under cursor.

        :return: Method success.
        :rtype: bool

def delete_lines(self):
        """
        Deletes the document lines under cursor.

        :return: Method success.
        :rtype: bool
        """

        cursor = self.textCursor()
        self.__select_text_under_cursor_blocks(cursor)
        cursor.removeSelectedText()
        cursor.deleteChar()
        return True