ios - awakeFromNib method is getting called twice UITableViewCell -

i using xib create uitableviewcell in view controller. registered cell class table view follows:

self.tableview.register(uinib(nibname: "thisweekcell", bundle: nil), forcellreuseidentifier: "thisweekcellidentifier")

in cellforrowat indexpath method dequeuing cell follows:

tableview.dequeuereusablecell(withidentifier: "thisweekcellidentifier") as! thisweekcell

when dequeuing cell, cell's awakefromnib method getting called twice. in first call outlet properties set in second call nil.

the problem facing is: none of constraints set in xib file getting reflected when displaying cell.