code: def forward(self, x):
      out = self.conv_offset_mask(x)
      o1, o2, mask = torch.chunk(out, 3, dim=1)
      offset = torch.cat((o1, o2), dim=1)
      mask = torch.sigmoid(mask)
      return modulated_deform_conv(
          x,
          offset,
          mask,
          self.weight,
          self.bias,
          self.stride,
          self.padding,
          self.dilation,
          self.groups,
          self.deformable_groups,
      )
  
imports: import math
  import torch
  import torch.nn
  from torch.nn.modules.utils import _pair
  from ..functions.deform_conv import deform_conv, modulated_deform_conv
label_desc: Use image node_id 3 for calling the ModulatedDeformConvPack obj's underlying member method code with example usage: obj.forward(x) and returns: modulated_deform_conv