Proposal:
Add the possibility to provide a custom HttpMessageHandler to InfluxDBClient e. g. for testing.

Current behavior:
ApiClient does have a settable RestClient property via which it is possible to inject a custom HttpMessageHandler.
However, it is not possible to inject that ApiClient into InfluxDBClient because the ApiClient construction is hard-coded into the InfluxDBClient ctor.
Atm I use reflection to overwrite the _apiClient field in InfluxDBClient after construction, which is a brittle hack.

Desired behavior:
Provide some way (ctor, options, anything) of reliably either setting the HttpMessageHandler or, less desirable IMHO the RestClient under the hood.

Alternatives considered:
Overwrite InfluxDBClient._apiClient via reflection.

Use case:
I am writing E2E unit tests for an application query flow from application to InfluxDB and back.
To include as much code as possible and be as realistic as possible, I did not mock InfluxDBClient, but used a traffic-replay of the CSV from a real InfluxDB for a real query with real (non-confidential) data.
A custom HttpMessageHandler returns that canned CSV.
This enables testing without guessing how the CSV is deserialized into FluxTable etc. and thus makes it more realistc and robust.