code: def forward(self, x):
      y = self.conv2(self.conv1(x))
      if self.add_shortcut:
          y = y + x
      return y
  
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 2 for calling the BottleNeck obj's underlying member method code with example usage: obj.forward(x) and returns: y