Alias null

[Len]

Benchmark showed 2 things:

• Explicitly comparing to null is faster than implicit casting (https://jsben.ch/pKNKz)
• Caching null in a global const is just as fast as using null directly everywhere while reducing file size (https://jsben.ch/LpFcF)

IS

If something is optional, explicit comparision to null is already used almost everywhere.
At any location null is used, it is used by its native name.

SHOULD

null should be cached in a global constant and that constant should be used everywhere instead.