def to_h
      h = RRRSpec.redis.hgetall(key)
      h['key'] = key
      h['trials'] = trials.map { |trial| { 'key' => trial.key } }
      h['taskset'] = { 'key' => h['taskset'] }
      RRRSpec.convert_if_present(h, 'estimate_sec') { |v| v.to_i }
      h
    end
def to_h
      h = RRRSpec.redis.hgetall(key)
      h['key'] = key
      h['trials'] = trials.map { |trial| { 'key' => trial.key } }
      h['taskset'] = { 'key' => h['taskset'] }
      RRRSpec.convert_if_present(h, 'estimate_sec') { |v| v.to_i }
      h
    end
==========================================================================
 Serialize