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: @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