@Test
  public void ethSyncingFalse() throws Exception {
    final String id = "007";
    final RequestBody body =
        RequestBody.create(
            "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"eth_syncing\"}",
            JSON);
    when(synchronizer.getSyncStatus()).thenReturn(Optional.empty());

    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
      assertThat(resp.code()).isEqualTo(200);
      // Verify general result format.
      final JsonObject json = new JsonObject(resp.body().string());
      testHelper.assertValidJsonRpcResult(json, id);
      // Evaluate result.
      assertThat(json.getBoolean("result")).isFalse();
    }
  }
Tests that empty batch requests are treated as invalid requests as per
http://www.jsonrpc.org/specification#batch.
ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/JsonRpcHttpServiceTest.java