public static @NotNull List<FileType> createSubtypes(@NotNull FileType originalType) {
    List<FileType> subtypes = new ArrayList<>();
    for (FileNameMatcher matcher : FileTypeManager.getInstance().getAssociations(originalType)) {
      if (matcher instanceof ExtensionFileNameMatcher) {
        String name =
          ((ExtensionFileNameMatcher)matcher).getExtension().equals(originalType.getDefaultExtension())
          ? originalType.getName()
          : getSubtypeName(originalType.getName(), (ExtensionFileNameMatcher)matcher);
        subtypes.add(new MyFileSubtype(originalType, matcher, name, matcher.getPresentableString()));
      }
    }
    return subtypes;
  }
public static @NotNull List<FileType> createSubtypes(@NotNull FileType originalType)