_.of() in 3.0 doesn't respect use.

[vqvu]

There's a new feature in 3.0 (not yet documented) called use that lets you extend the stream prototype. To allow top-level functions to create streams using the correct prototype, we bind the top-level object to the function's this reference.

Top-level functions must use this when constructing streams from scratch in order to be compliant. of doesn't do that.