code: func (p Bits) RowKeys() []string {
  	if !p.HasRowKeys() {
  		return nil
  	}
  	other := make([]string, len(p))
  	for i := range p {
  		other[i] = p[i].RowKey
  	}
  	return other
  }
docs: // RowKeys returns a slice of all the row keys.