[ Version ( since = "3.10" ) ]
public void insert (Widget child, int position)
Insert the child into the this at position.
If a sort function is set, the widget will actually be inserted at the calculated position and this function has the same effect of add.
If position is -1, or larger than the total number of items in the this, then the
child will be appended to the end.
| this |
a ListBox |
| child |
the Widget to add |
| position |
the position to insert |