question: @ SuppressWarnings ( "unchecked" ) public Promise < Result , Progress > reject ( Exception ex ) { List < FailCallback > failCallbacks ; List < AlwaysCallback > alwaysCallbacks ; synchronized ( this ) { validateInPendingState ( ) ; mState = STATE_REJECTED ; printStateChanged ( "REJECTED" ) ; mException = ex ; failCallbacks = mCallbacks . cloneFailCallbacks ( ) ; alwaysCallbacks = mCallbacks . cloneAlwaysCallbacks ( ) ; clearCallbacks ( ) ; } if ( failCallbacks . size ( ) > 0 || alwaysCallbacks . size ( ) > 0 ) { triggerAllFails ( failCallbacks ) ; triggerAllAlways ( alwaysCallbacks ) ; } return this ; }
target:  Rejects the promise, triggers any fail/always callbacks