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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 _sim_strlen(self, str_addr):
 """ Return the result of invoking the strlen simprocedure on `str_addr`. """


        from .. import SIM_PROCEDURES
        strlen = SIM_PROCEDURES['libc']['strlen']

        return self.inline_call(strlen, str_addr).ret_expr