public static PtrUIHandlerHolder removeHandler(PtrUIHandlerHolder head, PtrUIHandler handler) {
        if (head == null || handler == null || null == head.mHandler) {
            return head;
        }

        PtrUIHandlerHolder current = head;
        PtrUIHandlerHolder pre = null;
        do {

            // delete current: link pre to next, unlink next from current;
            // pre will no change, current move to next element;
            if (current.contains(handler)) {

                // current is head
                if (pre == null) {

                    head = current.mNext;
                    current.mNext = null;

                    current = head;
                } else {

                    pre.mNext = current.mNext;
                    current.mNext = null;
                    current = pre.mNext;
                }
            } else {
                pre = current;
                current = current.mNext;
            }

        } while (current != null);

        if (head == null) {
            head = new PtrUIHandlerHolder();
        }
        return head;
    }
A single linked list to wrap PtrUIHandler
ptr-lib/src/in/srain/cube/views/ptr/PtrUIHandlerHolder.java