Dropdown multi many to many

Hi @korchev ,

I tried implementing your solution here but cannot do the map at step 3...

|Error|CS1061|'IQueryable' does not contain a definition for 'map' and no accessible extension method 'map' accepting a first argument of type 'IQueryable' could be found (are you missing a using directive or an assembly reference?)

Without the map I am getting issues with casting the FormRef icollection (from getForm used as the drop down data) to the FormRef iqueryable.

What is map and why don't I have it?