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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 _construct_params(params, required_keys, opt_keys=None):
 """ Construct params list in order of given keys. """

        try:
            params_list = [params.pop(key) for key in required_keys]
        except KeyError as e:
            raise MissingParameter(
                'Missing expected request parameter: %s' % e)
        if opt_keys:
            params_list.extend([params.pop(key)
                                for key in opt_keys if key in params])
        return '/'.join(str(p) for p in params_list)