jetbrick-commons/src/main/java/jetbrick/collections/ArrayStack.java
public void clear() {
        int i = size;
        Object[] els = elements;
        while (i-- > 0) {
            els[i] = null;
        }
        this.size = 0;
    }
public void clear() {
        int i = size;
        Object[] els = elements;
        while (i-- > 0) {
            els[i] = null;
        }
        this.size = 0;
    }
Removes all of the elements from this stack.