<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def concretize_write_addr(self, addr, strategies=None):
 """ Concretizes an address meant for writing. :param addr: An expression for the address. :param strategies: A list of concretization strategies (to override the default). :returns: A list of concrete addresses. """


        if isinstance(addr, int):
            return [ addr ]
        elif not self.state.solver.symbolic(addr):
            return [ self.state.solver.eval(addr) ]

        strategies = self.write_strategies if strategies is None else strategies
        return self._apply_concretization_strategies(addr, strategies, 'store')