Hub.subscribe_quoted

You're seeing just the function subscribe_quoted, go back to Hub module for more information.
Link to this function

subscribe_quoted(channel_name, quoted_pattern, options \\ [])

Specs

subscribe_quoted(String.t(), any(), Hub.Channel.subscribe_options()) ::
  {:ok, Hub.Channel.subscription_ref()} | {:error, reason :: String.t()}

Subscribes to the quoted pattern in the given channel_name

example:

Hub.subscribe("global", quote do: %{count: count} when count > 42)