instance method structurally_incompatible_value?

# File activerecord/lib/active_record/relation/query_methods.rb, line 2659
      def structurally_incompatible_value?(method, values)
        v1, v2 = @values[method], values[method]

        # `and`/`or` are focused to combine where-like clauses, so it relaxes
        # the difference when other's multi values are uninitialized.
        return false if v1.is_a?(Array) && v2.nil?

        !(v1 == v2)
      end