public function scan(callable $accumulator, $seed = null)
    {
        return $this->lift(function () use ($accumulator, $seed) {
            return new ScanOperator($accumulator, $seed);
        });
    }
public function scan(callable $accumulator, $seed = null)
    {
        return $this->lift(function () use ($accumulator, $seed) {
            return new ScanOperator($accumulator, $seed);
        });
    }
public function scan ( callable $ accumulator , $ seed = null ) { return $ this -> lift ( function ( ) use ( $ accumulator , $ seed ) { return new ScanOperator ( $ accumulator , $ seed ) ; } ) ; }
Applies an accumulator function over an observable sequence and returns each intermediate result.
The optional seed value is used as the initial accumulator value.
For aggregation behavior with no intermediate results, see Observable.aggregate.

@param $accumulator
@param null $seed
@return AnonymousObservable
Applies an accumulator function over an observable sequence and returns each intermediate result . The optional seed value is used as the initial accumulator value . For aggregation behavior with no intermediate results see Observable . aggregate .