docs: def append(self, record):
          """
          Adds the passed +record+ to satisfy the query. Only intended to be
          used in conjunction with associations (i.e. do not use if self.record
          is None).
  
          Intended use case (DO THIS):
  
          post.comments.append(comment)
  
          NOT THIS:
  
          Query(Post).where(content="foo").append(post)
          """
          if self.record:
              self._validate_record(record)
              if self.join_args:
                  # As always, the related record is created when the primary
                  # record is saved
                  build_args = dict(self.where_query)
                  # The +final_join+ is what connects the record chain to the
                  # passed +record+
                  final_join = self.join_args[-2]
                  # don't need to worry about one-to-many through because
                  # there is not enough information to find or create the
                  # joining record
                  # i.e. in the Forum -> Thread -> Post example
                  # forum.posts.append(post) doesn't make sense since there
                  # is no information about what thread it will be attached to
                  # Thus, this only makes sense on many-to-many. BUT we still
                  # have to consider the case where there is a one-many-many
                  # To make that work, we need to treat this like when doing
                  # building
                  joining_relation = getattr(self.record, final_join['table'])
                  # Uses the lookup info in the join to figure out what ids to
                  # set, and where to get the id value from
                  joining_args = {final_join['on'][0]:
                                  getattr(record, final_join['on'][1])}
                  build_args.update(joining_args)
                  joining_record = joining_relation.build(**build_args)
                  self.record._related_records.append(joining_record)
              else:
                  # Add our id to their foreign key so that the relationship is
                  # created
                  setattr(record,
                          foreign_key(record, self.record),
                          self.record.id)
                  # Add to the list of related records so that it is saved when
                  # we are
                  self.record._related_records.append(record)