class RBS::NoSuperclassFoundError

def self.check!(type_name, env:, location:)
  env.class_decls.key?(type_name) or raise new(type_name: type_name, location: location)
end

def initialize(type_name:, location:)
  @type_name = type_name
  @location = location
  super "#{Location.to_string location}: Could not find super class: #{type_name}"
end