Task: Assess the emotional content of the tweet and classify 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 best represent the tweeter's mental state.
Tweet: Sometimes it takes #sadness to know happiness, #noise to appreciate #silence and absence to value presence.
This tweet contains emotions: 
anticipation, joy, optimism, sadness