Task: Analyze the tweet's sentiment and assign it to either 'neutral or no emotion' or one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Gloriosa Bazigaga on #Rwanda work: 'I lost relatives in genocide but 15 yrs of peacebuilding has given me optimism it's within our power'
This tweet contains emotions: 
optimism