Task: Evaluate the tweet for emotional cues and classify it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that indicate the tweeter's state of mind.
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