Set GridLayout row height in Vaadin

Set GridLayout row height in Vaadin

Very straight forward question, if you have a GridLayout defined in
Vaadin, how can you set the height of all / individual rows? E.g:
mainLayout = new GridLayout(2, 7);
mainLayout.setMargin(true);
mainLayout.setWidth("100%");
mainLayout.setHeight("100%");
// Set row[s] height?
Thanks in advance!