[support] Where to put code common to some computed_fields ?

Hi, I have added 4 computed fields to a node type (the "profile" node type, in case you wonder), and all of them have nearly the same code to compute their value. I'd like to create a function to write/debug the code only once, but where can I put it ? Would it work if I put it in the first field only ? My computed fields are save in the database (they are used in views), if that matters. Thanks, Xav PS: please Cc: me on answers