code: def add(self, root):
          
          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)
docs: Add an <xs:import/> to the specified schema root.
          @param root: A schema root.
          @type root: L{Element}