code: func (c *GCSCli) FitCompatibleLocation(loc string) error {
  	if c.StorageClass == "" {
  		var err error
  		if c.StorageClass, err = getDefaultStorageClass(loc); err != nil {
  			return err
  		}
  	}
  
  	_, regional := GCSRegionalLocations[loc]
  	_, multiRegional := GCSMultiRegionalLocations[loc]
  	if !(regional || multiRegional) {
  		return ErrUnknownLocation
  	}
  
  	if _, ok := GCSStorageClass[c.StorageClass]; !ok {
  		return ErrUnknownStorageClass
  	}
  
  	return validLocationStorageClass(loc, c.StorageClass)
  }
docs: // FitCompatibleLocation returns whether a provided Location
  // can have c.StorageClass objects written to it.
  //
  // When c.StorageClass is empty, a compatible default is filled in.
  //
  // nil return value when compatible, otherwise a non-nil explanation.