viewController(atRow:makeIfNecessary:)
Returns the content view controller associated with the specified row, or a new content view controller if desired.
Declaration
func viewController(atRow row: Int, makeIfNecessary makeIfNecesary: Bool) -> NSViewControllerParameters
Return Value
The content view controller associated with the specified row, if one exists. Returns nil if the row doesn’t have a content view controller and you don’t want to create one.