instance method structurally_incompatible_values_for

# File activerecord/lib/active_record/relation/query_methods.rb, line 2639
      def structurally_incompatible_values_for(other)
        values = other.values

        # A value set on neither relation can't differ, so only the values set
        # on either one are compared. When one differs, every incompatible
        # value is collected, in order, for the error message.
        if structurally_incompatible_key?(@values, values) || structurally_incompatible_key?(values, values)
          STRUCTURAL_VALUE_METHODS.select { |method| structurally_incompatible_value?(method, values) }
        else
          []
        end
      end