A list in which the user can expand a single item to view item details. See also the MultiListInlay variant.

By default, this control expects items to be a dictionary of the form:

    description: (content, usually a single line, that's always visible)
    content: (expanded content that appears when an item is selected)

This control implements the List Inlay user interface pattern discussed in the book "Designing Interfaces". This control was also the subject of a user interface blog post.