# File lib/polyamorous/activerecord_5.2_ruby_2/join_association.rb, line 30
    def build_constraint(klass, table, key, foreign_table, foreign_key)
      if reflection.polymorphic?
        super(klass, table, key, foreign_table, foreign_key)
        .and(foreign_table[reflection.foreign_type].eq(reflection.klass.name))
      else
        super(klass, table, key, foreign_table, foreign_key)
      end
    end