def process_projection(data)
      mutex.synchronize do
        projection_status = status[data[:projection]]
        projection_status.set_error data[:error], data[:backtrace]
        projection_status.event = data[:event]
      end
    end
def process_projection(data)
      mutex.synchronize do
        projection_status = status[data[:projection]]
        projection_status.set_error data[:error], data[:backtrace]
        projection_status.event = data[:event]
      end
    end
status of all projections received so far