How to use the darts.model_search.Network function in darts

def __init__(self, C, num_classes, layers, criterion, steps=4, multiplier=4, stem_multiplier=3):
    super(Network, self).__init__()
    self._C = C
    self._num_classes = num_classes
    self._layers = layers
    self._criterion = criterion
    self._steps = steps
    self._multiplier = multiplier

    C_curr = stem_multiplier*C
    self.stem = nn.Sequential(
      nn.Conv2d(3, C_curr, 3, padding=1, bias=False),
      nn.BatchNorm2d(C_curr)
    )
 
    C_prev_prev, C_prev, C_curr = C_curr, C_curr, C
    self.cells = nn.ModuleList()
    reduction_prev = False