code: def forward(self, inputs, ifshortcut):
      y = self._expand_conv(inputs, if_act=True)
      y = self._bottleneck_conv(y, if_act=True)
      y = self._linear_conv(y, if_act=False)
      if ifshortcut:
          y = paddle.add(inputs, y)
      return y
  
imports: import math
  import numpy
  import paddle
  from paddle import ParamAttr
  import paddle.nn
  import paddle.nn.functional
  from paddle.nn import Conv2D, BatchNorm, Linear, Dropout
  from paddle.nn import AdaptiveAvgPool2D, MaxPool2D, AvgPool2D
  from paddleseg.cvlibs import manager
  import ppmatting
label_desc: Use image node_id 2 for calling the InvertedResidualUnit obj's underlying member method code with example usage: obj.forward(inputs, ifshortcut) and returns: y