code: def _make_layers(
      self, c_in, c_hidden, c_out, stride_3x3, padding_3x3
  ):
      return nn.Sequential(
          nn.Conv2D(c_in, c_hidden, 1),
          nn.ReLU(),
          nn.Conv2D(c_hidden, c_out, 3, stride_3x3, padding_3x3),
          nn.ReLU(),
      )
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from ppdet.core.workspace import register
  from paddle.regularizer import L2Decay
  from paddle import ParamAttr
  from ..layers import AnchorGeneratorSSD
  from ..cls_utils import _get_class_default_kwargs
label_desc: Use image node_id 2 for calling the SSDExtraHead obj's underlying member method code with example usage: obj._make_layers(c_in, c_hidden, c_out, stride_3x3, padding_3x3) and returns: nn