Pass the default dropCheck result to dropCheckers

[taye]

interact(target)
  .dropzone(true)
  .dropChecker(function (pointer,            // pointer/event that ends drag
                         dropped,            // value from default drop check
                         dropzone,           // dropzone Interactable
                         dropElement,        // dropzone Element
                         draggable,          // draggable Interactable
                         draggableElement) { // Element being dragged

    // use the default value with another custom condition
    return dropped && someCondition;
  });