old_contents: function sin(arg) {
    // From: http://phpjs.org/functions
    // +   original by: Onno Marsman
    // *     example 1: sin(8723321.4);
    // *     returns 1: -0.9834330348825909
    return Math.sin(arg);
  }
  
new_contents: function sin(arg) {
    // From: http://phpjs.org/functions
    // +   original by: Onno Marsman
    // *     example 1: sin(8723321.4);
    // *     returns 1: -0.9834330348825929
    return Math.sin(arg);
  }
  
subject: Fix sin() example as per Firefox result (and Travis)