### Question:
DefaultGroupExtractor implements GroupExtractor { public ResourceType getResourceType(final HttpServletRequest request) { Validate.notNull(request); final String uri = request.getRequestURI(); Validate.notNull(uri); ResourceType type = null; try { type = ResourceType.get(FilenameUtils.getExtension(stripSessionID(uri))); } catch (final IllegalArgumentException e) { LOG.debug("[FAIL] Cannot identify resourceType for uri: {}", uri); } return type; }  String getGroupName(final HttpServletRequest request); ResourceType getResourceType(final HttpServletRequest request); String encodeGroupUrl(final String groupName, final ResourceType resourceType, final boolean minimize); boolean isMinimized(final HttpServletRequest request); static final String ATTR_INCLUDE_PATH; static final String PARAM_MINIMIZE; }### Answer:
@Test(expected = NullPointerException.class) public void cannotExtractResourceTypeWithNullUri() { groupExtractor.getResourceType(null); }