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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 begin(self):
 """ At the start of the run, we want to record the test execution information in the database. """

        exec_payload = ExecutionQueryPayload()
        exec_payload.execution_start_time = int(time.time() * 1000)
        self.execution_start_time = exec_payload.execution_start_time
        exec_payload.guid = self.execution_guid
        exec_payload.username = getpass.getuser()
        self.testcase_manager.insert_execution_data(exec_payload)