Task: Determine the dominant emotion in the tweet and classify it as either 'neutral or no emotion' or one of the eleven provided 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