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: @SalterUK second pair of scales I have bought that have stopped working after battery change. Is this an issue you are aware of?  #unhappy
This tweet contains emotions: 
anger, pessimism, sadness