pushPreferredHeight
Causes the minimum and/or natural height to grow if the new proposed sizes exceed the current minimum and natural height.
This is used by GtkCellAreaContext implementations during the request process over a series of GtkTreeModel rows to progressively push the requested height over a series of gtk_cell_area_get_preferred_height() requests.
Parameters
minimumHeight
the proposed new minimum height for @context
naturalHeight
the proposed new natural height for @context