code: def custom_yolov3(
      base_network_name,
      filters,
      anchors,
      strides,
      classes,
      dataset,
      pretrained_base=True,
      pretrained=False,
      norm_layer=BatchNorm,
      norm_kwargs=None,
      **kwargs,
  ):
      """Custom YOLO models."""
      pretrained_base = False if pretrained else pretrained_base
  
      if base_network_name == "darknet53":
          base_net = darknet53(
              pretrained=pretrained_base,
              norm_layer=norm_layer,
              norm_kwargs=norm_kwargs,
              **kwargs,
          )
          stages = [
              base_net.features[:15],
              base_net.features[15:24],
              base_net.features[24:],
          ]
      elif base_network_name == "mobilenet1.0":
          base_net = get_mobilenet(
              multiplier=1,
              pretrained=pretrained_base,
              norm_layer=norm_layer,
              norm_kwargs=norm_kwargs,
              **kwargs,
          )
          stages = [
              base_net.features[:33],
              base_net.features[33:69],
              base_net.features[69:-2],
          ]
      elif base_network_name == "mobilenet0.25":
          base_net = get_mobilenet(
              multiplier=0.25,
              pretrained=pretrained_base,
              norm_layer=norm_layer,
              norm_kwargs=norm_kwargs,
              **kwargs,
          )
          stages = [
              base_net.features[:33],
              base_net.features[33:69],
              base_net.features[69:-2],
          ]
      else:
          raise NotImplementedError(
              "Unsupported network: ", base_network_name
          )
  
      net = get_yolov3(
          name=base_network_name,
          stages=stages,
          filters=filters,
          anchors=anchors,
          strides=strides,
          classes=classes,
          dataset=dataset,
          pretrained=pretrained,
          **kwargs,
      )
  
      return net
  
imports: from __future__ import absolute_import
  from __future__ import division
  import os
  import warnings
  import numpy
  import mxnet
  from mxnet import gluon
  from mxnet import autograd
  from mxnet.gluon import nn
  from mxnet.gluon.nn import BatchNorm
  from .darknet import _conv2d, darknet53
  from ..mobilenet import get_mobilenet
  from .yolo_target import YOLOV3TargetMerger
  from ...loss import YOLOV3Loss
label_desc: Use image node_id 3 for calling a global function with example usage: custom_yolov3(base_network_name, filters, anchors, strides, classes, dataset, pretrained_base, pretrained, norm_layer, norm_kwargs) and returns: net