code: func (t *tOps) createFrom(src iterator.Iterator) (f *tFile, n int, err error) {
  	w, err := t.create()
  	if err != nil {
  		return
  	}
  
  	defer func() {
  		if err != nil {
  			w.drop()
  		}
  	}()
  
  	for src.Next() {
  		err = w.append(src.Key(), src.Value())
  		if err != nil {
  			return
  		}
  	}
  	err = src.Error()
  	if err != nil {
  		return
  	}
  
  	n = w.tw.EntriesLen()
  	f, err = w.finish()
  	return
  }
docs: // Builds table from src iterator.