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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 modelstandardfunctions(self):
 """Standard functions of the model class."""

        lines = Lines()
        lines.extend(self.doit)
        lines.extend(self.iofunctions)
        lines.extend(self.new2old)
        lines.extend(self.run)
        lines.extend(self.update_inlets)
        lines.extend(self.update_outlets)
        lines.extend(self.update_receivers)
        lines.extend(self.update_senders)
        return lines