public @NotNull Map<? extends VirtualFile, ? extends Charset> getAllMappings() {
    return myMapping.entrySet().stream()
      .map(e -> Pair.create(e.getKey().getFile(), e.getValue()))
      .filter(e -> e.getFirst() != null)
      .collect(Collectors.toMap(p -> p.getFirst(), p -> p.getSecond(), (c1, c2) -> c1));
  }
public @NotNull Map<? extends VirtualFile, ? extends Charset> getAllMappings()