code: func validateIsolation(hc *container.HostConfig) error {
  	// We may not be passed a host config, such as in the case of docker commit
  	if hc == nil {
  		return nil
  	}
  	if !hc.Isolation.IsValid() {
  		return fmt.Errorf("Invalid isolation: %q. Windows supports 'default', 'process', or 'hyperv'", hc.Isolation)
  	}
  	return nil
  }
docs: // validateIsolation performs platform specific validation of the
  // isolation in the hostconfig structure. Windows supports 'default' (or
  // blank), 'process', or 'hyperv'.