code: def __call__(self, rois, tgt_labels, tgt_gt_inds, inputs):
      gt_segms = inputs["gt_poly"]
  
      outs = generate_mask_target(
          gt_segms,
          rois,
          tgt_labels,
          tgt_gt_inds,
          self.num_classes,
          self.mask_resolution,
      )
  
      # mask_rois, mask_rois_num, tgt_classes, tgt_masks, mask_index, tgt_weights
      return outs
  
imports: import sys
  import paddle
  from ppdet.core.workspace import register, serializable
  from .target import rpn_anchor_target, generate_proposal_target, generate_mask_target, libra_generate_proposal_target
  import numpy
label_desc: Use image node_id 2 for calling the MaskAssigner obj's underlying member method code with example usage: obj.__call__(rois, tgt_labels, tgt_gt_inds, inputs) and returns: outs