code: def check_4_elements(cls, v: List[float]) -> List[float]:
      if len(v) != 4:
          raise ValueError("bbox must have 4 elements")
      return v
  
imports: from collections import Counter
  from typing import List, Optional, Tuple
  from pydantic import BaseModel, field_validator
  import ftfy
  from marker.bbox import boxes_intersect_pct, multiple_boxes_intersect
  from marker.settings import settings
label_desc: Use image node_id 1 for calling the BboxElement obj's underlying member method code with example usage: obj.check_4_elements(cls, v) and returns: v