code: def count_masks(self, texts):
      return [
          len([x for x in text.split() if x.startswith("<extra_id_")])
          for text in texts
      ]
  
imports: import numpy
  from abc import ABC, abstractmethod
  from .text_utils import extract_non_overlapping_ngrams
label_desc: Use image node_id 4 for calling the PerturbationModel obj's underlying member method code with example usage: obj.count_masks(texts) and returns: unknown