module Tapioca::ConstantLocator

or where metaprogramming was used via +eval+, etc.
about situations where the class was opened prior to +require+ing,
Returns the files in which this class or module was opened. Doesn't know

def files_for(klass)
  name = String === klass ? klass : NAME.bind(klass).call
  files = @class_files[name]
  files || Set.new
end