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: 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