private boolean isTypeInvalid(final Object id) {
    for (final Class<?> validType : VALID_ID_TYPES) {
      if (validType.isInstance(id)) {
        return false;
      }
    }

    return true;
  }
The JSON spec says "The use of Null as a value for the id member in a Request object is
discouraged" Both geth and parity accept null values, so we decided to support them as well.
ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/JsonRpcRequestId.java