class_docstr: CSPDarkNet backbone.
  Args:
      arch (str): Architecture of CSPDarkNet, from {P5, P6, X}, default as X,
          and 'X' means used in YOLOX, 'P5/P6' means used in YOLOv5.
      depth_mult (float): Depth multiplier, multiply number of channels in
          each layer, default as 1.0.
      width_mult (float): Width multiplier, multiply number of blocks in
          CSPLayer, default as 1.0.
      depthwise (bool): Whether to use depth-wise conv layer.
      act (str): Activation function type, default as 'silu'.
      return_idx (list): Index of stages whose feature maps are returned.
code: def out_shape(self):
      return [
          ShapeSpec(channels=c, stride=s)
          for c, s in zip(self._out_channels, self.strides)
      ]
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddle import ParamAttr
  from paddle.regularizer import L2Decay
  from ppdet.core.workspace import register, serializable
  from ppdet.modeling.initializer import conv_init_
  from ..shape_spec import ShapeSpec
label_desc: Use image node_id 3 for calling the CSPDarkNet obj's underlying member method code with example usage: obj.out_shape() and returns: unknown