### Question:
SearchModelFactory { public static LogicalSearchFilter not(final SearchFilter filter) { return ImmutableLogicalFilter.not(filter); } private  SearchModelFactory(); static SearchResult newSearchResult(final JsonArray items, final long nextPageOffset); static SearchResult emptySearchResult(); static SearchResult newSearchResult(final JsonObject jsonObject); static SearchResult newSearchResult(final String jsonString); static SearchResultBuilder newSearchResultBuilder(); static SearchResultBuilder newSearchResultBuilder(final SearchResult searchResult); static LogicalSearchFilter and(final SearchFilter filter1, final SearchFilter filter2,
            final SearchFilter... furtherFilters); static LogicalSearchFilter or(final SearchFilter filter1, final SearchFilter filter2,
            final SearchFilter... furtherFilters); static LogicalSearchFilter not(final SearchFilter filter); static SearchProperty property(final JsonPointer propertyPath); static SearchProperty property(final CharSequence propertyPath); static SearchQuery newSearchQuery(final SearchFilter filter); static SearchQueryBuilder newSearchQueryBuilder(final SearchFilter filter); static SortOption newSortOption(final List<SortOptionEntry> sortOptionEntries); static SortOption newSortOption(final CharSequence propertyPath, final SortOptionEntry.SortOrder sortOrder); @Deprecated static SortOptionEntry newSortOptionEntry(final SortOptionEntry.SortOrder sortOrder,
            final CharSequence propertyPath); static SortOptionEntry newSortOptionEntry(final CharSequence propertyPath,
            final SortOptionEntry.SortOrder sortOrder); static LimitOption newLimitOption(final int offset, final int count); static SizeOption newSizeOption(final int size); static CursorOption newCursorOption(final String cursor);  }### Answer:
@Test(expected = NullPointerException.class) public void tryToCreateNotFilterWithNullFilter() { SearchModelFactory.not(null); }
@Test public void createNotFilter() { final LogicalSearchFilter searchFilter = SearchModelFactory.not(filterMock); final Collection<SearchFilter> filters = searchFilter.getFilters(); assertThat(filters).containsOnly(filterMock); }