class_docstr: Collects information on gold and predicted clusters across documents.
  Can be used to retrieve weighted LEA-score for them.
code: def __init__(self):
      self._p = 0.0
      self._r = 0.0
      self._p_weight = 0.0
      self._r_weight = 0.0
  
imports: from typing import Hashable, List, Tuple
  from stanza.models.coref.const import EPSILON
label_desc: Use image node_id 1 to create a new ClusterChecker object  with example: obj = ClusterChecker()