@Nullable
  public static ContractReturnValue valueOf(@NotNull String value) {
    return switch (value) {
      case "_" -> returnAny();
      case "fail" -> fail();
      case "true" -> returnTrue();
      case "false" -> returnFalse();
      case "null" -> returnNull();
      case "!null" -> returnNotNull();
      case "new" -> returnNew();
      case "this" -> returnThis();
      default -> {
        if (value.startsWith("param")) {
          String suffix = value.substring("param".length());
          try {
            int paramNumber = Integer.parseInt(suffix) - 1;
            if (paramNumber >= 0 && paramNumber <= MAX_SUPPORTED_PARAMETER) {
              yield new ParameterReturnValue(paramNumber);
            }
          }
          catch (NumberFormatException ignored) {
            // unexpected non-integer suffix: ignore
          }
        }
        yield null;
      }
    };
  }
@Nullable
  public static ContractReturnValue valueOf(@NotNull String value)