@Override
  public int hashCode() {
    return Objects.hashCode(id);
  }
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