code: def coveredPairs(blocker: blocking.Fingerprinter, records):
      cover = {}
  
      n_records = len(records)
  
      for predicate in blocker.predicates:
          pred_cover = collections.defaultdict(set)
  
          for id, record in records.items():
              blocks = predicate(record)
              for block in blocks:
                  pred_cover[block].add(id)
  
          if not pred_cover:
              continue
  
          max_cover = max(len(v) for v in pred_cover.values())
          if max_cover == n_records:
              continue
  
          pairs = frozenset(
              pair
              for block in pred_cover.values()
              for pair in itertools.combinations(sorted(block), 2)
          )
          if pairs:
              cover[predicate] = pairs
  
      return cover
  
imports: from __future__ import annotations
  import collections
  import functools
  import itertools
  import logging
  import math
  import random
  from abc import ABC
  from typing import TYPE_CHECKING, overload
  from warnings import warn
  from .None import blocking, branch_and_bound
label_desc: Use image node_id 4 for calling the DedupeBlockLearner obj's underlying member method code with example usage: obj.coveredPairs(blocker, records) and returns: cover