question: public boolean addOperationAtFirst ( Operation operation ) { if ( isRunning ) { if ( operationHandlerThreadHandler == null ) return false ; return operationHandlerThreadHandler . postAtFrontOfQueue ( new AndroidOperation ( this , operation ) ) ; } else { return operationQueue . add ( new AndroidOperation ( this , operation , AndroidOperation . Type . ATFIRST , null , 0 ) ) ; } }
target:  add operation to OperationQueue. The Operation will be executed on the next iteration through the operation queue.