code: def urltool(classqname, filt, reverse):
      
      filt = re.compile(filt or '.*')
  
      rootCls = namedAny(classqname)
      rules = list(_iterClass(rootCls))
      arr = []
      for item in sorted(rules):
          if item.subKlein:
              continue
  
          matched = filt.search(item.rulePath)
          matched = not matched if reverse else matched
          if matched:
              arr.append(tuple(item.toOpenAPIPath()))
  
      openapi3 = openapi.OpenAPI()
      for pathPath, pathItem in arr:
          if pathPath in openapi3.paths:
              openapi3.paths[pathPath].merge(pathItem)
          else:
              openapi3.paths[pathPath] = pathItem
      print(yaml.dump(openapi3, default_flow_style=False))
docs: Dump all urls branching from a class as OpenAPI 3 documentation
  
      The class must be given as a FQPN which points to a Klein() instance.
  
      Apply optional [FILT] as a regular expression searching within urls. For
      example, to match all urls beginning with api, you might use '^/api'