TreeViewColumn.cellGetSize

void cellGetSize(out int xOffset, out int yOffset, out int width, out int height)

Obtains the width and height needed to render the column. This is used primarily by the [gtk.tree_view.TreeView].

`xOffset`	location to return x offset of a cell relative to cell_area
`yOffset`	location to return y offset of a cell relative to cell_area
`width`	location to return width needed to render a cell
`height`	location to return height needed to render a cell

Use GtkColumnView instead