Where is the definition of "prvIdleTask"

Sorry for that maybe the question is too fooly, I can not find the definition of “prvIdleTask”
/* Create the idle task without storing its handle. */
xReturn = xTaskCreate( prvIdleTask, “IDLE”, tskIDLE_STACK_SIZE, ( void * ) NULL, ( tskIDLE_PRIORITY | portPRIVILEGE_BIT ), NULL );

Thank you very much!

Here it is: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/master/tasks.c#L3423

Thanks.