# File lib/test/unit/assertions.rb, line 601
      def assert_nothing_thrown(message="", &proc)
        _wrap_assertion do
          assert(block_given?, "Should have passed a block to assert_nothing_thrown")
          begin
            proc.call
          rescue NameError, ArgumentError, ThreadError => error
            raise unless UncaughtThrow[error.class] =~ error.message
            tag = $1
            tag = tag[1..-1].intern if tag[0, 1] == ":"
            full_message = build_message(message,
                                         "<?> was thrown when nothing was expected",
                                         tag)
            flunk(full_message)
          end
          assert(true, "Expected nothing to be thrown")
        end
      end