Task: Determine the prevailing emotional tone of the tweet, categorizing it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that most accurately represent the tweeter's mental state.
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