code: public static Throwable onOperatorError(@Nullable Subscription subscription,
  			Throwable error,
  			Context context) {
  		return onOperatorError(subscription, error, null, context);
  	}
docs: Map an "operator" error given an operator parent {@link Subscription}. The
  result error will be passed via onError to the operator downstream.
  {@link Subscription} will be cancelled after checking for fatal error via
  {@link Exceptions#throwIfFatal(Throwable)}.
  
  @param subscription the linked operator parent {@link Subscription}
  @param error the callback or operator error
  @param context a context that might hold a local error consumer
  @return mapped {@link Throwable}