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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 postprocess(self):
 """Submit a postprocessing script after collation"""

        assert self.postscript
        envmod.setup()
        envmod.module('load', 'pbs')

        cmd = 'qsub {script}'.format(script=self.postscript)

        cmd = shlex.split(cmd)
        rc = sp.call(cmd)
        assert rc == 0, 'Postprocessing script submission failed.'