code: function(elements, options, done) {
              elements = ensureAnArray(elements);
              options = merge(options, {
                  pos: [300, 300],
                  scale: 2,
                  duration: 250,
                  radius: 100,
                  touches: 2
              });
  
              var touches = getTouches(options.pos, elements, options.touches);
              triggerGesture(elements, touches, options, function() {
                  done && setTimeout(done, 25);
              });
          }
docs: pinch
  @param {HTMLElement|Array} elements
  @param options
  @param done