class RSpec::Mocks::InstanceMethodStasher

def restore
  return unless @method_is_stashed
  if @klass.__send__(:method_defined?, @method)
    @klass.__send__(:undef_method, @method)
  end
  @klass.__send__(:alias_method, @method, stashed_method_name)
  @klass.__send__(:remove_method, stashed_method_name)
  @method_is_stashed = false
end