code: def get_ipv4_table(self):
          
  
          vpn_table = self._global_tables.get(RF_IPv4_UC)
          # Lazy initialize the table.
          if not vpn_table:
              vpn_table = Ipv4Table(self._core_service, self._signal_bus)
              self._global_tables[RF_IPv4_UC] = vpn_table
              self._tables[(None, RF_IPv4_UC)] = vpn_table
  
          return vpn_table
docs: Returns global IPv4 table.
  
          Creates the table if it does not exist.