old_contents: 
  
  class ReportDataSource(object):
      slug = ''
  
      def __init__(self, config=None):
          """
          :param config: dictionary containing configuration for this data source.
           e.g.
           {
              'startdate': date(2013, 1, 1),
              'enddate': date(2013, 1, 31),
              'user_id': 'abc'
           }
          """
          self.config = config
  
      def configure(self, config):
          """
          :param config: dictionary containing configuration for this data source.
           Overrides any config supplied to the constructor.
          """
          self.config = config
  
      def slugs(self):
          """
          Intention: Override
  
          :return: A list of available slugs.
          """
          return []
  
      def get_data(self, start=None, limit=None):
          """
          Intention: Override
  
          :param slugs: List of slugs to return for each row. Return all values if slugs = None or [].
          :return: A list of dictionaries mapping slugs to values.
  
          e.g.
          [{'village': 'Mazu', 'births': 30, 'deaths': 28},{...}]
          """
  
          return {}
  
      def get_query_strings(self):
          return NotImplemented
  
      def get_total_records(self):
          return 0
  
new_contents: 
  
  class ReportDataSource(object):
      slug = ''
  
      def __init__(self, config=None):
          """
          :param config: dictionary containing configuration for this data source.
           e.g.
           {
              'startdate': date(2013, 1, 1),
              'enddate': date(2013, 1, 31),
              'user_id': 'abc'
           }
          """
          self.config = config
  
      def configure(self, config):
          """
          :param config: dictionary containing configuration for this data source.
           Overrides any config supplied to the constructor.
          """
          self.config = config
  
      def slugs(self):
          """
          Intention: Override
  
          :return: A list of available slugs.
          """
          return []
  
      def get_data(self, start=None, limit=None):
          """
          Intention: Override
  
          :param slugs: List of slugs to return for each row. Return all values if slugs = None or [].
          :return: A list of dictionaries mapping slugs to values.
  
          e.g.
          [{'village': 'Mazu', 'births': 30, 'deaths': 28},{...}]
          """
  
          return [{}]
  
      def get_query_strings(self):
          return NotImplemented
  
      def get_total_records(self):
          return 0
  
subject: fix default