Classes are also values in Ruby. Sorbet has two ways to describe the type of these class objects: `T.class_of(...)` and `T::Class[...]`.| sorbet.org
Union types declare that a value either has one type, or some other type. The| sorbet.org
> This page describes the syntax of method signatures, or `sig`s. For a complete| sorbet.org
Sorbet can track when a value is allowed to be `nil`, or when a value of a| sorbet.org