code: def namespaces(
              self,
              name=None,
              function=None,
              recursive=None,
              allow_empty=None):
          
  
          return (
              self._find_multiple(
                  scopedef.scopedef_t._impl_matchers[namespace_t.namespace],
                  name=name,
                  function=function,
                  recursive=recursive,
                  allow_empty=allow_empty)
          )
docs: Returns a set of namespace declarations that match
          a defined criteria.