docstr: load n records for testing
docstr_tok: ["load","n","records","for","testing"]
code: def load_records(self, n=1, buffer_size=100):
      """load n records for testing"""
      # sleep 1/10 s, to ensure timestamp is different to previous calls
      time.sleep(0.01)
      msg_ids = []
      for i in range(n):
          msg = self.session.msg("apply_request", content=dict(a=5))
          msg["buffers"] = [os.urandom(buffer_size)]
          rec = init_record(msg)
          msg_id = msg["header"]["msg_id"]
          msg_ids.append(msg_id)
          self.db.add_record(msg_id, rec)
      return msg_ids
  
imports: import logging
  import os
  import tempfile
  import time
  from datetime import datetime, timedelta
  from unittest import TestCase
  import pytest
  from jupyter_client.session import Session
  from ipyparallel import util
  from ipyparallel.controller.dictdb import DictDB
  from ipyparallel.controller.hub import init_record
  from ipyparallel.controller.sqlitedb import SQLiteDB
  from ipyparallel.util import utc
label_desc: Use image node_id 3 for calling the TaskDBTest obj's underlying member method code with example usage: obj.load_records(n, buffer_size) and returns: msg_ids