code: def build_conflict_dict(key_list, val_list):
      
      key_to_vals = defaultdict(list)
      for key, val in zip(key_list, val_list):
          key_to_vals[key].append(val)
      return key_to_vals
docs: Builds dict where a list of values is associated with more than one key
  
      Args:
          key_list (list):
          val_list (list):
  
      Returns:
          dict: key_to_vals
  
      CommandLine:
          python -m utool.util_dict --test-build_conflict_dict
  
      Example:
          >>> # ENABLE_DOCTEST
          >>> from utool.util_dict import *  # NOQA
          >>> import utool as ut
          >>> key_list = [  1,   2,   2,   3,   1]
          >>> val_list = ['a', 'b', 'c', 'd', 'e']
          >>> key_to_vals = build_conflict_dict(key_list, val_list)
          >>> result = ut.repr4(key_to_vals)
          >>> print(result)
          {
              1: ['a', 'e'],
              2: ['b', 'c'],
              3: ['d'],
          }