code: func LookupInGroup(field groupField, value interface{}, n int) ([]*Group, error) {
  	iEntries, err := lookUp(&Group{}, field, value, n)
  	if err != nil {
  		return nil, err
  	}
  
  	// == Convert to type group
  	valueSlice := reflect.ValueOf(iEntries)
  	entries := make([]*Group, valueSlice.Len())
  
  	for i := 0; i < valueSlice.Len(); i++ {
  		entries[i] = valueSlice.Index(i).Interface().(*Group)
  	}
  
  	return entries, err
  }
docs: // LookupInGroup looks up a group by the given values.
  //
  // The count determines the number of fields to return:
  //   n > 0: at most n fields
  //   n == 0: the result is nil (zero fields)
  //   n < 0: all fields