Replace filter in vaadin filter-table addon

Hello fellow vaadin developers.
I have a problem related to the FilteringTable addon by Teppo Kurki.
I need to replace a filter on filter table, since most of them work with Strings, I need an Integer search for a particular column like in the demo, or if that’s too hard, just an Integer search would be nice (when I hit 1, I need to get only rows with number 1 in them). I have searched here and there for my answer and code examples, but being a relative begginer in Vaadin, I haven’t found the answer by myself. It would be wonderful if somebody could help me out with this question. Thank you in advace.