public static boolean areEqualCharsets(@NotNull List<? extends DiffContent> contents) {
    boolean sameCharset = areEqualDocumentContentProperties(contents, DocumentContent::getCharset);
    boolean sameBOM = areEqualDocumentContentProperties(contents, DocumentContent::hasBom);
    return sameCharset && sameBOM;
  }
public static boolean areEqualCharsets(@NotNull List<? extends DiffContent> contents)