presto-main/src/main/java/io/prestosql/execution/QueryStateMachine.java/QueryStateMachine/transitionToDispatching
class QueryStateMachine:    public boolean transitionToDispatching()
    {
        queryStateTimer.beginDispatching();
        return queryState.setIf(DISPATCHING, currentState -> currentState.ordinal() < DISPATCHING.ordinal());
    }