# Missing from this documentation

Here are some of the things not (yet) covered in this documentation:

- Interoperating with Node streams (see `example.js` in `@promistream/from-node-stream` - this is pretty trivial and it's even entirely valid to *only* use Node streams in your pipeline, using this wrapper)
- Concurrency (this is illustrated in the `example.js` for the `@promistream/parallelize` package)
- Branching (this is illustrates in the `example.js` of various `@promistream/fork-*` packages)
- Converging/merging (currently only illustrated in the `example.js` of the `@promistream/merge-concatenate` package - merge streams are still being worked on)
- The exact details of what source/sink streams are responsible for (part of the unfinished spec)
- How the internal `peek` API works (this is responsible for making concurrency work reliably)