instance method add_relations_to_bind_values

# File activerecord/lib/active_record/relation/query_methods.rb, line 1166
    def add_relations_to_bind_values(attributes)
      if attributes.is_a?(Hash)
        attributes.each_value do |value|
          if value.is_a?(ActiveRecord::Relation)
            self.bind_values += value.arel.bind_values + value.bind_values
          else
            add_relations_to_bind_values(value)
          end
        end
      end
    end