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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 to_string(self, nspair=None):
 """Converts the Saml object to a string containing XML. :param nspair: A dictionary of prefixes and uris to use when constructing the text representation. :return: String representation of the object """

        if not nspair and self.c_ns_prefix:
            nspair = self.c_ns_prefix

        if nspair:
            self.register_prefix(nspair)

        return ElementTree.tostring(self._to_element_tree(), encoding="UTF-8")