Reports references to the classes NilClass, TrueClass, and FalseClass in type signatures. Usage of these classes is unnecessarily verbose.

A quick fix is available to replace the NilClass, TrueClass, or FalseClass usage with its respective literal.

Example:

# 'NilClass' referenced instead of 'nil', ...
type example = NilClass | TrueClass | FalseClass

After the quick fix:

type example = nil | true | false