当前行为：节点可以降到任何级别（我可以将父节点作为子节点和孙子节点，我可以使Child节点作为父节点和孙子节点，使孙子节点作为父子节点） 预期的行为：树应该只允许我们将节点放到同一级别 即，父节点应始终是父节点，子节点应始终是子节点，大子节点应始终是大子节点。
Data=
[
{
"label": "Documents",
"data": "Documents Folder",
"expandedIcon": "fa fa-folder-open",
"collapsedIcon": "fa fa-folder",
"children": [{
"label": "Work",
"data": "Work Folder",
"expandedIcon": "fa fa-folder-open",
"collapsedIcon": "fa fa-folder",
"children": [{"label": "Expenses.doc", "icon": "fa fa-file-word-o", "data": "Expenses Document"}, {"label": "Resume.doc", "icon": "fa fa-file-word-o", "data": "Resume Document"}]
},
{
"label": "Home",
"data": "Home Folder",
"expandedIcon": "fa fa-folder-open",
"collapsedIcon": "fa fa-folder",
"children": [{"label": "Invoices.txt", "icon": "fa fa-file-word-o", "data": "Invoices for this month"}]
}]
},
{
"label": "Pictures",
"data": "Pictures Folder",
"expandedIcon": "fa fa-folder-open",
"collapsedIcon": "fa fa-folder",
"children": [
{"label": "barcelona.jpg", "icon": "fa fa-file-image-o", "data": "Barcelona Photo"},
{"label": "logo.jpg", "icon": "fa fa-file-image-o", "data": "PrimeFaces Logo"},
{"label": "primeui.png", "icon": "fa fa-file-image-o", "data": "PrimeUI Logo"}]
},
{
"label": "Movies",
"data": "Movies Folder",
"expandedIcon": "fa fa-folder-open",
"collapsedIcon": "fa fa-folder",
"children": [{
"label": "Al Pacino",
"data": "Pacino Movies",
"children": [{"label": "Scarface", "icon": "fa fa-file-video-o", "data": "Scarface Movie"}, {"label": "Serpico", "icon": "fa fa-file-video-o", "data": "Serpico Movie"}]
},
{
"label": "Robert De Niro",
"data": "De Niro Movies",
"children": [{"label": "Goodfellas", "icon": "fa fa-file-video-o", "data": "Goodfellas Movie"}, {"label": "Untouchables", "icon": "fa fa-file-video-o", "data": "Untouchables Movie"}]
}]
}
];
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