code: def get_schemaloc_string(self, ns_uris=None, sort=False, delim="\n"):
          
          if not ns_uris:
              ns_uris = six.iterkeys(self.__ns_uri_map)
  
          if sort:
              ns_uris = sorted(ns_uris)
  
          schemalocs = []
  
          for ns_uri in ns_uris:
              ni = self.__lookup_uri(ns_uri)
  
              if ni.schema_location:
                  schemalocs.append("{0.uri} {0.schema_location}".format(ni))
  
          if not schemalocs:
              return ""
  
          return 'xsi:schemaLocation="{0}"'.format(delim.join(schemalocs))
docs: Constructs and returns a schemalocation attribute.  If no
          namespaces in this set have any schema locations defined, returns
          an empty string.
  
          Args:
              ns_uris (iterable): The namespaces to include in the constructed
                  attribute value.  If None, all are included.
              sort (bool): Whether the sort the namespace URIs.
              delim (str): The delimiter to use between namespace/schemaloc
                  *pairs*.
  
          Returns:
              str: A schemalocation attribute in the format:
                  ``xsi:schemaLocation="nsuri schemaloc<delim>nsuri2 schemaloc2<delim>..."``