code: def ohem_batch(self, scores, gt_texts, training_masks, ohem_ratio=3):
      selected_masks = []
      for i in range(scores.shape[0]):
          selected_masks.append(
              self.ohem_single(
                  scores[i, :, :],
                  gt_texts[i, :, :],
                  training_masks[i, :, :],
                  ohem_ratio,
              )
          )
  
      selected_masks = paddle.concat(selected_masks, 0).astype(
          "float32"
      )
      return selected_masks
  
file_path: PaddleOCR/ppocr/losses/det_pse_loss.py
imports: import paddle
  from paddle import nn
  from paddle.nn import functional
  import numpy
  from ppocr.utils.iou import iou
label_desc: Use image node_id 5 for calling the PSELoss obj's underlying member method code with example usage: obj.ohem_batch(scores, gt_texts, training_masks, ohem_ratio) and returns: selected_masks