docs: def insert(self, table, data_list, return_cols='id'):
          """
          Create a bulk insert statement which is much faster (~2x in tests with 10k & 100k rows and n cols)
          for inserting data then executemany()
  
          TODO: Is there a limit of length the query can be? If so handle it.
          """
          data_list = copy.deepcopy(data_list)  # Create deepcopy so the original list does not get modified
          # Make sure that `data_list` is a list
          if not isinstance(data_list, list):
              data_list = [data_list]
          # Make sure data_list has content
          if len(data_list) == 0:
              # No need to continue
              return []
  
          # Data in the list must be dicts (just check the first one)
          if not isinstance(data_list[0], dict):
              logger.critical("Data must be a list of dicts")
              # Do not return here, let the exception handle the error that will be thrown when the query runs
  
          # Make sure return_cols is a list
          if return_cols is None or len(return_cols) == 0 or return_cols[0] is None:
              return_cols = ''
          elif not isinstance(return_cols, list):
              return_cols = [return_cols]
  
          if len(return_cols) > 0:
              return_cols = 'RETURNING ' + ','.join(return_cols)
  
          try:
              with self.getcursor() as cur:
                  query = "INSERT INTO {table} ({fields}) VALUES {values} {return_cols}"\
                          .format(table=table,
                                  fields='"{0}"'.format('", "'.join(data_list[0].keys())),
                                  values=','.join(['%s'] * len(data_list)),
                                  return_cols=return_cols,
                                  )
                  values = []
                  for row in [tuple(v.values()) for v in data_list]:
                      values.append(_check_values(row))
  
                  query = cur.mogrify(query, values)
                  cur.execute(query)
  
                  try:
                      return cur.fetchall()
                  except Exception:
                      return None
  
          except Exception as e:
              logger.exception("Error inserting data")
              logger.debug("Error inserting data: {data}".format(data=data_list))
              raise e.with_traceback(sys.exc_info()[2])