def METHOD_NAME(self):
    """This method determines if job was completed successfully and returns ``True`` if exit code is 0.
    According to https://help.altair.com/2021.1.3/PBS%20Professional/PBSAdminGuide2021.1.3.pdf section 14.9 Job Exit Status Codes we have the following
     - Exit Code:  X < 0         - Job could not be executed
     - Exit Code: 0 <= X < 128   -  Exit value of Shell or top-level process
     - Exit Code: X >= 128       - Job was killed by signal
     - Exit Code: X == 0         - Job executed was a successful
    """
    return self._exitcode == 0