public static @Nullable @DialogMessage String checkIfValidJsonSchema(@NotNull Project project, @NotNull VirtualFile file) {
    final long length = file.getLength();
    final String fileName = file.getName();
    if (length > MAX_SCHEMA_LENGTH) {
      return JsonBundle.message("schema.reader.file.too.large", fileName, length);
    }
    if (length == 0) {
      return JsonBundle.message("schema.reader.file.empty", fileName);
    }
    try {
      readFromFile(project, file);
    }
    catch (Exception e) {
      final String message = JsonBundle.message("schema.reader.file.not.found.or.error", fileName, e.getMessage());
      Logger.getInstance(JsonSchemaReader.class).info(message);
      return message;
    }
    return null;
  }
public static @Nullable @DialogMessage String checkIfValidJsonSchema(@NotNull Project project, @NotNull VirtualFile file)