Task: Analyze the tweet's sentiment and assign it to either 'neutral or no emotion' or one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Harking back to 2012 - DT's challenge to @POTUS...I will give...DT a hearty thank you...if he will release his tax returns....
This tweet contains emotions: 
joy