@Test
  public void missingTagParameterBlockTransactions() {
    final JsonRpcRequestContext request = requestWithParams(true);

    final Throwable thrown = catchThrowable(() -> ethGetBlockNumber().response(request));

    assertThat(thrown)
        .isInstanceOf(InvalidJsonRpcParameters.class)
        .hasMessageContaining("Invalid block parameter");
  }
The Tag | Quantity is the first parameter, either a String or a number
ethereum/api/src/integration-test/java/org/hyperledger/besu/ethereum/api/jsonrpc/methods/fork/frontier/EthGetBlockByNumberIntegrationTest.java