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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 _make_callsites(self, stack_pointer_tracker=None):
 """ Simplify all function call statements. :return: None """


        # Computing reaching definitions
        rd = self.project.analyses.ReachingDefinitions(func=self.function, func_graph=self.graph, observe_all=True)

        for key in self._blocks:
            block = self._blocks[key]
            csm = self.project.analyses.AILCallSiteMaker(block, reaching_definitions=rd)
            if csm.result_block:
                ail_block = csm.result_block
                simp = self.project.analyses.AILBlockSimplifier(ail_block, stack_pointer_tracker=stack_pointer_tracker)
                self._blocks[key] = simp.result_block

        self._update_graph()