code: def fetch_auth(request_auth):
      """Find the request auth from registered providers based on the auth provider's name.
      The auth provider's name can be provided through environment variable `MLFLOW_TRACKING_AUTH`.
  
      This function iterates through all request auth providers in the registry. Additional context
      providers can be registered as described in
      :py:class:`mlflow.tracking.request_auth.RequestAuthProvider`.
  
      :param request_auth: The name of request auth provider.
      :return: The auth object.
      """
  
      for auth_provider in _request_auth_provider_registry:
          if auth_provider.get_name() == request_auth:
              return auth_provider.get_auth()
  
      warnings.warn(
          f"Could not find any registered plugin for {request_auth}. "
          "No authentication header will be added. Please check your "
          "provider documentation for installing the right plugin or "
          "correct provider name."
      )
  
imports: import warnings
  import entrypoints
label_desc: Use image node_id 1 for calling a global function with example usage: fetch_auth(request_auth) and returns: auth_provider