code: def forward(self, inputs, residual=None):
      if residual is None:
          residual = inputs
  
      out = self.conv1(inputs)
      out = F.relu(out)
  
      out = self.conv2(out)
  
      out = paddle.add(x=out, y=residual)
      out = F.relu(out)
  
      return out
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from ppdet.core.workspace import register, serializable
  from ppdet.modeling.layers import ConvNormLayer
  from ..shape_spec import ShapeSpec
label_desc: Use image node_id 2 for calling the BasicBlock obj's underlying member method code with example usage: obj.forward(inputs, residual) and returns: out