getComplianceLevelSupportedFeatures() {
    if (this.imageInfo === undefined) {
      return undefined;
    }
    const version = this.getImageApiVersion();
    const level = this.getComplianceLevelFromProfile(version);
    if (level === undefined) {
      return IIIF_PROFILE_VALUES['none']['none'];
    }
    return IIIF_PROFILE_VALUES[version][level];
  }
@return {SupportedFeatures|undefined} Image formats, qualities and region / size calculation
methods that are supported by the IIIF service.