R""(
Test whether connecting to a remote Nix store via SSH works:
Test whether a URL is a valid binary cache:
Test whether the Nix daemon is up and running:
This command tests whether a particular Nix store (specified by the argument --store
url) can be accessed. What this means is dependent on the type of the store. For instance, for an SSH store it means that Nix can connect to the specified machine.
If the command succeeds, Nix returns a exit code of 0 and does not print any output.
)""