Task: Categorize the tweet's emotional tone as either 'neutral or no emotion' or identify the presence of one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: @antoboyle I so wish you could someday come to Spain with the play, I can't believe I'm not going to see it #sad
This tweet contains emotions: 
sadness