code: func (x *Index) ExistingFileSchemas(wholeRef ...blob.Ref) (WholeRefToFile, error) {
  	schemaRefs := make(WholeRefToFile)
  	for _, v := range wholeRef {
  		newRefs, err := x.existingFileSchemas(v)
  		if err != nil {
  			return nil, err
  		}
  		schemaRefs[v.String()] = newRefs
  	}
  	return schemaRefs, nil
  }
docs: // ExistingFileSchemas returns the file schemas for the provided file contents refs.