code: def configure(config=None, bind_in_runtime=True):
      
      global _INJECTOR
  
      with _INJECTOR_LOCK:
          if _INJECTOR:
              raise InjectorException('Injector is already configured')
  
          _INJECTOR = Injector(config, bind_in_runtime=bind_in_runtime)
          logger.debug('Created and configured an injector, config=%s', config)
          return _INJECTOR
docs: Create an injector with a callable config or raise an exception when already configured.