# cast<RS, RT> method

StreamTransformer<RS, RT> cast <RS, RT>()

Provides a `StreamTransformer<RS, RT>` view of this stream transformer.

The resulting transformer will check at run-time that all data events of the stream it transforms are actually instances of `S`, and it will check that all data events produced by this transformer are actually instances of `RT`.

## Implementation

    StreamTransformer<RS, RT> cast<RS, RT>();