def add(self, root):
        """
        Add an <xs:import/> to the specified schema root.
        @param root: A schema root.
        @type root: L{Element}
        """
        node = Element('import', ns=self.xsdns)
        node.set('namespace', self.ns)
        if self.location is not None:
            node.set('schemaLocation', self.location)
        log.debug('%s inserted', node)
        root.insert(node)
Add an <xs:import/> to the specified schema root.
        @param root: A schema root.
        @type root: L{Element}