Why did my view overlap？

[LeeKuma]

`private void initTreeView(){
TreeNode root = TreeNode.root();
for (Department department:departments){
root.addChild(addDepartment(department));
}
tView = new AndroidTreeView(this, root);
tView.setDefaultAnimation(true);
tView.setDefaultContainerStyle(R.style.TreeNodeStyleCustom);
tView.setDefaultViewHolder(IconTreeItemHolder.class);
tView.setDefaultNodeClickListener(nodeClickListener);
tView.setDefaultNodeLongClickListener(nodeLongClickListener);
containerView.addView(tView.getView());
}

private TreeNode addDepartment(Department department){
    TreeNode departmentRoot = new TreeNode(new IconTreeItemHolder.IconTreeItem(R.string.ic_people, department.getName()));
    List<User> members = department.getMembers();
    if (members!=null){
        for (User user:members){
            TreeNode member = new TreeNode(new IconTreeItemHolder.IconTreeItem(R.string.ic_person, user.getUsername()));
            departmentRoot.addChild(member);
            userList.add(user);
        }
    }
    List<Department> children = department.getChildren();
    if (children!=null){
        for (Department department1:children){
            departmentRoot.addChild(addDepartment(department1));
        }
    }
    return departmentRoot;
}`