code: def retrieveVals(self):
          
          for iface in self._ifaceList:
              if self._reqIfaceList is None or iface in self._reqIfaceList:
                  if (self.graphEnabled('wanpipe_traffic') 
                      or self.graphEnabled('wanpipe_errors')):
                      stats = self._ifaceStats.get(iface)
                      if stats:
                          graph_name = 'wanpipe_traffic_%s' % iface
                          if self.hasGraph(graph_name):
                              for field in ('rxpackets', 'txpackets'):
                                  self.setGraphVal(graph_name, field, 
                                                   stats.get(field))
                          graph_name = 'wanpipe_errors_%s' % iface
                          if self.hasGraph(graph_name):
                              for field in ('rxerrs', 'txerrs', 'rxframe', 'txcarrier',
                                  'rxdrop', 'txdrop', 'rxfifo', 'txfifo'):
                                  self.setGraphVal(graph_name, field, 
                                                   stats.get(field))
                  if (self.graphEnabled('wanpipe_pri_errors') 
                      or self.graphEnabled('wanpipe_rxlevel')):
                      try:
                          stats = self._wanpipeInfo.getPRIstats(iface)
                      except:
                          stats = None
                      if stats:
                          graph_name = 'wanpipe_pri_errors_%s' % iface
                          if self.hasGraph(graph_name):
                              for field in ('linecodeviolation', 
                                            'farendblockerrors',
                                            'crc4errors', 'faserrors'):
                                  self.setGraphVal(graph_name, field, 
                                                   stats.get(field))
                          if self.hasGraph('wanpipe_rxlevel'):
                              self.setGraphVal('wanpipe_pri_rxlevel', 
                                               iface, stats.get('rxlevel'))
docs: Retrieve values for graphs.