code: def __init__(self, in_channel, neck_type="None", data_format="NCHW"):
      super(BlazeNeck, self).__init__()
      self.neck_type = neck_type
      self.reture_input = False
      self._out_channels = in_channel
      if self.neck_type == "None":
          self.reture_input = True
      if "fpn" in self.neck_type:
          self.fpn = FPN(
              self._out_channels[0], self._out_channels[1], name="fpn"
          )
          self._out_channels = [
              self._out_channels[0] // 2,
              self._out_channels[1] // 2,
          ]
      if "ssh" in self.neck_type:
          self.ssh1 = SSH(
              self._out_channels[0], self._out_channels[0], name="ssh1"
          )
          self.ssh2 = SSH(
              self._out_channels[1], self._out_channels[1], name="ssh2"
          )
          self._out_channels = [
              self._out_channels[0],
              self._out_channels[1],
          ]
  
imports: import paddle
  import paddle.nn.functional
  from paddle import ParamAttr
  import paddle.nn
  from paddle.nn.initializer import KaimingNormal
  from ppdet.core.workspace import register, serializable
  from ..shape_spec import ShapeSpec
label_desc: Use image node_id 1 to create a new BlazeNeck object from inherited base classes: nn with example: obj = BlazeNeck(in_channel, neck_type, data_format)