In the hours leading up to the much-anticipated series finale of the popular crime drama Line of Duty, co-star Vicky McClure shared a hilarious video with her fans on Sunday.The actress, who plays Detective Inspector Kate Fleming in the hit BBC show, shared the behind-the-scenes footage of her friendly banter with co-stars Martin Compston and Adrian Dunbar.The video showed the trio enjoying a sing-along together while on set featuring the famous subway covered in graffiti behind them – a popular