:param linenum: The line number of the frame.
        :type linenum: int
        :param indent: The indentation level of the frame.
        :type indent: int
        :param path:
        :type path: Path
        :param field_name:
        :type field_name: str
        :param field_value:
        :type field_value: str

def append_sibling_field(self, linenum, indent, field_name, field_value):
        """
        :param linenum: The line number of the frame.
        :type linenum: int
        :param indent: The indentation level of the frame.
        :type indent: int
        :param path:
        :type path: Path
        :param field_name:
        :type field_name: str
        :param field_value:
        :type field_value: str
        """
        frame = self.current_frame()
        assert frame.indent is not None and frame.indent == indent
        self.pop_frame()
        self.append_child_field(linenum, indent, field_name, field_value)