### Question:
CRSUtils { public static String extractSRSCode(String srs) { if (isSrsUrlDefinition(srs)) { return EPSG_PREFIX + srs.substring(srs.lastIndexOf("/") + 1); } else { String[] srsParts = srs.split(":"); return EPSG_PREFIX + srsParts[srsParts.length - 1]; } } private  CRSUtils(CRSAuthorityFactory crsFactory); Point createPoint(Double x, Double y, String srs); Point createPoint(Double x, Double y, Double z, String srs); Geometry createLineString(Coordinate[] coordinates, String srs); GeometryFactory createGeometryFactory(); GeometryFactory createGeometryFactory(String srsId); static int getSrsIdFrom(final String srs); static String extractSRSCode(String srs); static int getSrsIdFromEPSG(String srs); Point transformOuterToInner(Point point, String srcFrame); Geometry transformOuterToInner(Geometry geometry, String srcFrame); Geometry transformInnerToOuter(Geometry geometry, String destFrame); Geometry transform(Geometry geometry, String srcFrame, String destFrame); Geometry parseWkt(String wkt); boolean isLatLonAxesOrder(String outer); static CRSUtils createEpsgStrictAxisOrder(); static CRSUtils createEpsgForcedXYAxisOrder(); static CRSUtils createEpsgReferenceHelper(Hints hints); static final int EPSG_WGS84; static final String DEFAULT_CRS; }### Answer:
@Test public void testExtractSRSCode() { String smallCaseUrn = "urn:ogc:def:crs:epsg::4326"; String capitalCaseUrn = "URN:OGC:DEF:CRS:EPSG:3.5:4326"; String mixedCaseUrn = "UrN:OfC:dEf:crs:EPSG::4323426"; String capitalEpsgLink = "http: String smallCaseEpsgLink = "http: assertValidEpsgShortCut("EPSG:4326", smallCaseUrn); assertValidEpsgShortCut("EPSG:4326", capitalCaseUrn); assertValidEpsgShortCut("EPSG:4323426", mixedCaseUrn); assertValidEpsgShortCut("EPSG:4324336", capitalEpsgLink); assertValidEpsgShortCut("EPSG:4326", smallCaseEpsgLink); }