code: func (q *query) Exclude(fields ...string) {
  	if q.hasIncludes() {
  		q.setError(errors.New("zoom: cannot use both Include and Exclude modifiers on a query"))
  		return
  	}
  	q.excludes = append(q.excludes, fields...)
  }
docs: // Exclude specifies one or more field names which will *not* be read from the
  // database and scanned. Any other fields *will* be read and scanned into the
  // resulting models when the query is run. You can only use one of Include or
  // Exclude, not both on the same query. Exclude will set an error if you try to
  // use it with Include 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.