code: func (q *query) Include(fields ...string) {
  	if q.hasExcludes() {
  		q.setError(errors.New("zoom: cannot use both Include and Exclude modifiers on a query"))
  		return
  	}
  	q.includes = append(q.includes, fields...)
  }
docs: // Include specifies one or more field names which will be read from the
  // database and scanned into the resulting models when the query is run. Field
  // names which are not specified in Include will not be read or scanned. You can
  // only use one of Include or Exclude, not both on the same query. Include will
  // set an error if you try to use it with Exclude on the same query. The error,
  // same as any other error that occurs during the lifetime of the query, is not
  // returned until the query is executed. When the query is executed the first
  // error that occurred during the lifetime of the query object (if any) will be
  // returned.