# File lib/mspec/matchers/output.rb, line 55
55:   def negative_failure_message
56:     out = ""
57:     out << "  $stdout: #{@stdout.chomp.dump}\n" unless @out.nil?
58:     out << "  $stderr: #{@stderr.chomp.dump}\n" unless @err.nil?
59:     ["Expected output not to be:\n", out]
60:   end