code: function (error, reason, details) {                                                                     // 73
      var self = this;                                                                                      // 74
                                                                                                            // 75
      // String code uniquely identifying this kind of error.                                               // 76
      self.error = error;                                                                                   // 77
                                                                                                            // 78
      // Optional: A short human-readable summary of the error. Not                                         // 79
      // intended to be shown to end users, just developers. ("Not Found",                                  // 80
      // "Internal Server Error")                                                                           // 81
      self.reason = reason;                                                                                 // 82
                                                                                                            // 83
      // Optional: Additional information about the error, say for                                          // 84
      // debugging. It might be a (textual) stack trace if the server is                                    // 85
      // willing to provide one. The corresponding thing in HTTP would be                                   // 86
      // the body of a 404 or 500 response. (The difference is that we                                      // 87
      // never expect this to be shown to end users, only developers, so                                    // 88
      // it doesn't need to be pretty.)                                                                     // 89
      self.details = details;                                                                               // 90
                                                                                                            // 91
      // This is what gets displayed at the top of a stack trace. Current                                   // 92
      // format is "[404]" (if no reason is set) or "File not found [404]"                                  // 93
      if (self.reason)                                                                                      // 94
        self.message = self.reason + ' [' + self.error + ']';                                               // 95
      else                                                                                                  // 96
        self.message = '[' + self.error + ']';                                                              // 97
    }
docs: 72