def _fixed_source_line(self):
line = self.lineno<EOL>_node = self<EOL>try:<EOL><INDENT>while line is None:<EOL><INDENT>_node = next(_node.get_children())<EOL>line = _node.lineno<EOL><DEDENT><DEDENT>except StopIteration:<EOL><INDENT>_node = self.parent<EOL>while _node and line is None:<EOL><INDENT>line = _node.lineno<EOL>_node = _node.parent<EOL><DEDENT><DEDENT>return line<EOL>
Attempt to find the line that this node appears on.

        We need this method since not all nodes have :attr:`lineno` set.

        :returns: The line number of this node,
            or None if this could not be determined.
        :rtype: int or None