differring row heights return this.getRowProperty("index");

I need to set different code heights for different rows in the grid; I found this in the Version 1 forums, but have several questions about it:

function rowNumber(){
return this.getRowProperty("index");
}
obj.getRowTemplate().setClass("row", rowNumber);

First, does this still apply to version 2?

Second what is this doing, exactly? I understand what setting the row template's class does... but I'm slightly confused by what we're accomplishing with this snip of code (other than perhaps to set evern row's css class to "row"??)