code: def __init__(self, in_channels):
      super(FPN_Down_Fusion, self).__init__()
      out_channels = [32, 64, 128]
  
      self.h0_conv = ConvBNLayer(
          in_channels[0],
          out_channels[0],
          3,
          1,
          act=None,
          name="fpn_down_h0",
      )
      self.h1_conv = ConvBNLayer(
          in_channels[1],
          out_channels[1],
          3,
          1,
          act=None,
          name="fpn_down_h1",
      )
      self.h2_conv = ConvBNLayer(
          in_channels[2],
          out_channels[2],
          3,
          1,
          act=None,
          name="fpn_down_h2",
      )
  
      self.g0_conv = ConvBNLayer(
          out_channels[0],
          out_channels[1],
          3,
          2,
          act=None,
          name="fpn_down_g0",
      )
  
      self.g1_conv = nn.Sequential(
          ConvBNLayer(
              out_channels[1],
              out_channels[1],
              3,
              1,
              act="relu",
              name="fpn_down_g1_1",
          ),
          ConvBNLayer(
              out_channels[1],
              out_channels[2],
              3,
              2,
              act=None,
              name="fpn_down_g1_2",
          ),
      )
  
      self.g2_conv = nn.Sequential(
          ConvBNLayer(
              out_channels[2],
              out_channels[2],
              3,
              1,
              act="relu",
              name="fpn_down_fusion_1",
          ),
          ConvBNLayer(
              out_channels[2],
              out_channels[2],
              1,
              1,
              act=None,
              name="fpn_down_fusion_2",
          ),
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import paddle
  from paddle import nn
  import paddle.nn.functional
  from paddle import ParamAttr
label_desc: Use image node_id 1 to create a new FPN_Down_Fusion object from inherited base classes: nn with example: obj = FPN_Down_Fusion(in_channels)