code: def exists_in_registry(category, namespace, name):
      
      selected_registry = [re for re in registry if re.category==category and re.namespace==namespace and re.name == name]
      if len(selected_registry)>0:
          return True
      return False
docs: See if a given category, namespace, name combination exists in the registry
      category - See registrycategories.  Type of module
      namespace - Namespace of the module, defined in settings
      name - the lowercase name of the module