code: def MergeConditionNets(name, condition_nets, relation):
      """
      Merge multi condition nets into a single condition nets.
  
      Args:
          name: name of the new condition net.
          condition_nets: a list of condition nets. The last external_output
                          of each condition net must be single bool value.
          relation: can be 'And' or 'Or'.
  
      Returns:
          - A new condition net. Its last external output is relation of all
            condition_nets.
      """
      if not isinstance(condition_nets, list):
          return condition_nets
      if len(condition_nets) <= 1:
          return condition_nets[0] if condition_nets else None
  
      merged_net = core.Net(name)
      for i in range(len(condition_nets)):
          net_proto = condition_nets[i].Proto()
          assert (
              net_proto.device_option
              == merged_net.Proto().device_option
          )
          assert net_proto.type == merged_net.Proto().type
          merged_net.Proto().op.extend(net_proto.op)
          merged_net.Proto().external_input.extend(
              net_proto.external_input
          )
          # discard external outputs as we're combining them together
          curr_cond = GetConditionBlobFromNet(condition_nets[i])
          if i == 0:
              last_cond = curr_cond
          else:
              last_cond = merged_net.__getattr__(relation)(
                  [last_cond, curr_cond]
              )
          # merge attributes
          for k, v in condition_nets[i]._attr_dict.items():
              merged_net._attr_dict[k] += v
  
      merged_net.AddExternalOutput(last_cond)
  
      return merged_net
  
imports: from caffe2.python import core
label_desc: Use image node_id 10 for calling a global function with example usage: MergeConditionNets(name, condition_nets, relation) and returns: merged_net, condition_nets, unknown