The child of the host element to insert the widget before.
Ordinarily the following checks should be performed:
The widget should have no parent
The widget should not be attached, and its node should not be a child of document.body
The host should be a child of document.body
We often violate the last condition.
The child of the host element to insert the widget before. Ordinarily the following checks should be performed: The widget should have no parent The widget should not be attached, and its node should not be a child of document.body The host should be a child of document.body We often violate the last condition.