class RBS::InvalidVarianceAnnotationError

def initialize(type_name:, param:, location:)

def initialize(type_name:, param:, location:)
  @type_name = type_name
  @param = param
  @location = location
  super "#{Location.to_string location}: Type parameter variance error: #{param.name} is #{param.variance} but used as incompatible variance"
end