code: def _merge_wheres_to_has(self, has_query, relation):
          
          relation_query = relation.get_base_query()
  
          has_query.merge_wheres(relation_query.wheres, relation_query.get_bindings())
  
          self._query.merge_bindings(has_query.get_query())
docs: Merge the "wheres" from the relation query to a has query.
  
          :param has_query: The has query
          :type has_query: Builder
  
          :param relation: The relation to count
          :type relation: eloquent.orm.relations.Relation