def call(context)
      raise "You should implement call yourself"
    end
The magic happens here. Because you have access to the Context, you can add your own setups, hookups,
etc. +call+ will be called before any tests are run, but after the Context is configured. Though
something will likely be returned, do not put any faith in what that will be.

@param [Riot::Context] context the Context instance that will be prepared by registered middleware