description

# moveNext method Null safety

Future<bool> moveNext ()

Wait for the next stream value to be available.

Returns a future which will complete with either `true` or `false`. Completing with `true` means that another event has been received and can be read as current. Completing with `false` means that the stream iteration is done and no further events will ever be available. The future may complete with an error, if the stream produces an error, which also ends iteration.

The function must not be called again until the future returned by a previous call is completed.

## Implementation

    Future<bool> moveNext();