[MdListItem] Programatically open expandable list items

[Tamakiwan]

Maybe there is a way to open expandable items that I'm not aware of, but I couldn't get an expandable item to open and close programatically. There is no way for an expandable list item to be open by default, or close the rest of expandable items when a new one is clicked.

Maybe getting the md-active class to the <md-list-item md-expand> element to actually expand the element? This class has no effect whatsover if added to the element as of now.