code: def _pad_1x1_to_3x3_tensor(self, kernel1x1):
      if kernel1x1 is None:
          return 0
      else:
          padding_size = (self.kernel_size - 1) // 2
          return nn.functional.pad(
              kernel1x1,
              [padding_size, padding_size, padding_size, padding_size],
          )
  
file_path: PaddleDetection/ppdet/modeling/backbones/mobileone.py
imports: import paddle
  import paddle.nn
  from paddle import ParamAttr
  from paddle.regularizer import L2Decay
  from paddle.nn.initializer import Normal, Constant
  from ppdet.modeling.ops import get_act_fn
  from ppdet.modeling.layers import ConvNormLayer
label_desc: Use image node_id 5 for calling the MobileOneBlock obj's underlying member method code with example usage: obj._pad_1x1_to_3x3_tensor(kernel1x1) and returns: int, nn