Get all the clients in a dict of {status: [client_list]}.

def GetClientsByStatus(self):
    """Get all the clients in a dict of {status: [client_list]}."""
    started = self.GetClients()
    completed = self.GetCompletedClients()
    outstanding = started - completed

    return {
        "STARTED": started,
        "COMPLETED": completed,
        "OUTSTANDING": outstanding
    }