Represents the various high-level states the a page can be in.
error: 10 The page is currently in the error state, but can be refreshed in an attempt to get out of this state.
loaded: 3 The page is fully loaded and can be refreshed and, if possible, submitted.
loading: 2 The page is currently being loaded.
offline: 1 The page was loaded in the offline mode, thus not refreshable.
refreshing: 4 The page is currently refreshing its data.