Creates a widget of class classname. Argument classname can be any of the strings returned by [[#qtuiloaderavailablewidgets][qtuiloader.availableWidgets()]. The optional argument parent specifies the parent widget and the optional argument name specifies the object name.

When argument parent is nil or not specified, the new widget is owned by the Lua interpreter and is automatically destroyed when the garbage collector determines that it is no longer referenced.