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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def build_stats_for_chain(self, build_chain_id):
 """Returns a list of Build tuples for all elements in the build chain. This method allows insight into the runtime of each configuratio inside the build chain. """

        json_form = self.__retrieve_as_json(self.build_chain_path % build_chain_id)
        builds = [{'build_id': build[u'id'], 'configuration_id': build[u'buildTypeId']} for build in json_form[u'build']]

        return [
            BuildStat(
                build['build_id'],
                build['configuration_id'],
                self.__build_duration_for_id(build['build_id']),
                self.__build_start_date_for_id(build['build_id']))
            for build in builds
        ]