# File lib/polyamorous/activerecord_5.2_ruby_2/join_dependency.rb, line 58
    def join_constraints(outer_joins, join_type)
      joins = join_root.children.flat_map { |child|
        if join_type == Arel::Nodes::OuterJoin
          make_polyamorous_left_outer_joins join_root, child
        else
          make_polyamorous_inner_joins join_root, child
        end
      }

      joins.concat outer_joins.flat_map { |oj|
        if join_root.match? oj.join_root
          walk(join_root, oj.join_root)
        else
          oj.join_root.children.flat_map { |child|
            make_outer_joins(oj.join_root, child)
          }
        end
      }
    end