Finding specific button in window via AccessibilityService

poc.java

public static AccessibilityNodeInfo findNoButton(final AccessibilityNodeInfo source, final String keyword) {
        Queue<AccessibilityNodeInfo> queue = new ArrayDeque<>();
        if (source == null) {
            return null;
        }
        queue.add(source);
        while (!queue.isEmpty()) {
            AccessibilityNodeInfo cur = queue.poll();
            for (int i = 0; i < cur.getChildCount(); i++) {
                AccessibilityNodeInfo child = cur.getChild(i);
                String childText = child.getText() + "";
                if (childText.equals(keyword)) {
                    return child;
                }
                queue.add(child);
            }
        }
        return null;
    }