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: @Uber_RSA when you click over and over again for a cupcake but there are no vehicles available... #sadness
This tweet contains emotions: 
pessimism, sadness