class_docstr: Instance segmentation head for SSD model.
class_docstr_tok: ["Instance","segmentation","head","for","SSD","model","."]
code: def forward(
      self, x: Tensor, boxes: Tensor, *args, **kwargs
  ) -> Tensor:
      rois = self.roi_align(x, boxes)
      rois = self.seg_head(rois)
      return rois
  
imports: from typing import Optional, Tuple
  import torch
  from torch import Tensor, nn
  from torchvision.ops.roi_align import RoIAlign
  from cvnets.layers import ConvLayer2d, SeparableConv2d, TransposeConvLayer2d
  from cvnets.misc.init_utils import initialize_conv_layer
  from cvnets.modules import BaseModule
label_desc: Use image node_id 4 for calling the SSDInstanceHead obj's underlying member method code with example usage: obj.forward(x, boxes) and returns: rois