code: def _render_sources(dataset, tables):
      
  
      if isinstance(tables, dict):
          if tables.get('date_range', False):
              try:
                  dataset_table = '.'.join([dataset, tables['table']])
                  return "FROM (TABLE_DATE_RANGE([{}], TIMESTAMP('{}'),"\
                      " TIMESTAMP('{}'))) ".format(dataset_table,
                                                   tables['from_date'],
                                                   tables['to_date'])
              except KeyError as exp:
                  logger.warn(
                      'Missing parameter %s in selecting sources' % (exp))
  
      else:
          return "FROM " + ", ".join(
              ["[%s.%s]" % (dataset, table) for table in tables])
docs: Render the source part of a query.
  
      Parameters
      ----------
      dataset : str
          The data set to fetch log data from.
      tables : Union[dict, list]
          The tables to fetch log data from
  
      Returns
      -------
      str
          A string that represents the "from" part of a query.