<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_summary_data(self, group_name, section_name, data):
 """ Set the summary data for an analysis group. :param group_name: The name of the analysis group. :param section_name: The analysis step. This will become a subfolder in the Summary section. :param data: A dictionary containing keys which are the summary fields, and values which are the summary values. """

        self.assert_writeable()
        group = 'Analyses/{}/Summary/{}'.format(group_name, section_name)
        self._add_group(group, data)