@callback connect(endpoint :: Endpoint.t(), start_options :: [Arangox.start_option()]) ::
  {:ok, socket()} | {:error, exception_or_reason()}

Receives an Arangox.Endpoint struct and all the start options from Arangox.start_link/1.

The socket returned from this callback gets placed in the :socket field of an Arango.Connection struct (a connection's state) to be used by the other callbacks as needed. It can be anything, a tuple, another struct, whatever the client needs.

It's up to the client to consolidate the :connect_timeout, :transport_opts and :client_opts options.

@callback request(request :: Arangox.Request.t(), state :: Arangox.Connection.t()) ::
  {:ok, Arangox.Response.t(), Arangox.Connection.t()}
  | {:error, exception_or_reason(), Arangox.Connection.t()}

Receives a Arangox.Request struct and a connection's state (an Arangox.Connection struct), and returns an Arangox.Response struct or error (or exception struct), along with the new state (which doesn't necessarily need to change).

Arangox handles the encoding and decoding of request and response bodies, and merging headers.

If a connection is lost, this may return {:error, :noproc, state} to force a disconnect, otherwise an attempt to reconnect may not be made until the next request hitting this process fails.