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The column picker contains:
Available Columns on the left.
Chosen Columns on the right.
At the top of each list:
A search bar above each list (optional). This allows the user to quickly locate specific items.
A list checkbox, allowing users to select / deselect all the items on that list.
If only some of the items are selected, the list checkbox will show a “partially selected” state (see Check Box Checkbox).A textual indicator, showing the number of existing items and the number of selected items, where relevant.
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