def activation_text(activation):
    """Return single activation text"""
    extra = '(still running)'
    if activation.finish:
        extra = 'to {a.finish} ({d} microseconds)'.format(d=activation.
            duration, a=activation)
    result = ['', 'Activation #{a.id} from {a.start} {extra}'.format(extra=
        extra, a=activation)]
    activation.show(print_=lambda x, offset=0: result.append(offset *
        '&nbsp;' + x))
    return result
