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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 set_scope(self, include=None, exclude=None):
 """ Sets `scope`, the "start point" for the audit. Args: include: A list of css selectors specifying the elements that contain the portion of the page that should be audited. Defaults to auditing the entire document. exclude: This arg is not implemented in this ruleset. Examples: To check only the `div` with id `foo`:: page.a11y_audit.config.set_scope(["div#foo"]) To reset the scope to check the whole document:: page.a11y_audit.config.set_scope() """

        if include:
            self.scope = u"document.querySelector(\"{}\")".format(
                u', '.join(include)
            )
        else:
            self.scope = "null"

        if exclude is not None:
            raise NotImplementedError(
                "The argument `exclude` has not been implemented in "
                "AxsAuditConfig.set_scope method."
            )