ReferenceError: MediaStream is not defined

### Your environment.
  - Version: *1.7.2*
  - Runtime: NodeJS v14.16.1
  - Other Information - *stacktraces, related issues, suggestions how to fix, links for us to have context*

### What did you do?
Running the code in readme with ts-node

### What did you expect?
The code running

### What happened?
Got an error of MediaStream is not defined