code: func Concat(slices ...[]interface{}) []interface{} {
  	offset := 0
  	for _, slice := range slices {
  		offset += len(slice)
  	}
  	concat := make([]interface{}, offset)
  	offset = 0
  	for _, slice := range slices {
  		for i, e := range slice {
  			concat[offset+i] = e
  		}
  		offset += len(slice)
  	}
  	return concat
  }
docs: // Concatenate slices into a single slice