LexicalIncludePaths { public static boolean hasHeaderExtension(@NotNull String filename) { String extension = FilenameUtils.getExtension(filename); return HEADER_FILE_EXTENSIONS.contains(extension); }  static boolean hasHeaderExtension(@NotNull String filename); @NotNull static String findCommonParentFolder(@NotNull Collection<String> folders); @NotNull static String trimPathSeparators(@NotNull String path); @NotNull static Matcher matchFolderToRegex(@NotNull Pattern pattern, @NotNull File folder); @NotNull
  static final ImmutableSet<String> HEADER_FILE_EXTENSIONS; }
@Test public void testHeaderExtension() { assertThat(LexicalIncludePaths.hasHeaderExtension("header")).isTrue(); assertThat(LexicalIncludePaths.hasHeaderExtension("header.h")).isTrue(); assertThat(LexicalIncludePaths.hasHeaderExtension("header.inl")).isTrue(); assertThat(LexicalIncludePaths.hasHeaderExtension("header.cpp")).isFalse(); }