code: def get_active_nodes(self):
          
          # the -1 4 -1 args are the filters <proxy_id> <type> <server_id>,
          # -1 for all proxies, 4 for servers only, -1 for all servers
          stats_response = self.send_command("show stat -1 4 -1")
          if not stats_response:
              return []
  
          lines = stats_response.split("\n")
          fields = lines.pop(0).split(",")
          # the first field is the service name, which we key off of so
          # it's not included in individual node records
          fields.pop(0)
  
          active_nodes = collections.defaultdict(list)
  
          for line in lines:
              values = line.split(",")
              service_name = values.pop(0)
              active_nodes[service_name].append(
                  dict(
                      (fields[i], values[i])
                      for i in range(len(fields))
                  )
              )
  
          return active_nodes
docs: Returns a dictionary of lists, where the key is the name of a service
          and the list includes all active nodes associated with that service.