code: func (as *Step) SetSummary(value string) bool {
  	if as.hasSummary {
  		if as.Text[0] == value {
  			return false
  		}
  
  		as.Text[0] = value
  	} else {
  		as.Text = append(as.Text, "")
  		copy(as.Text[1:], as.Text)
  		as.Text[0] = value
  		as.hasSummary = true
  	}
  	return true
  }
docs: // SetSummary sets the Step's summary text.
  //
  // The summary is implemented as the first line of step component text. If no
  // summary is currently defined, one will be inserted; otherwise, the current
  // summary will be replaced.