augment a function

augment.js

    var augment = function (base, extra, context) {
        return (function () {
          return function () {
            base.apply(context || this, arguments);
            extra.apply(context || this, arguments);
          };
        })();
      };
      
    // usage  
    console.log = augment(console.log, function(){
        console.warn("console.log was called");    
    });