check_to

# File lib/uri/mailto.rb, line 170
    def check_to(v)
      return true unless v
      return true if v.size == 0

      v.split(/[,;]/).each do |addr|
        # check url safety as path-rootless
        if /\A(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*\z/ !~ addr
          raise InvalidComponentError,
            "an address in 'to' is invalid as URI #{addr.dump}"
        end

        # check addr-spec
        # don't s/\+/ /g
        addr.gsub!(/%\h\h/, URI::TBLDECWWWCOMP_)
        if EMAIL_REGEXP !~ addr
          raise InvalidComponentError,
            "an address in 'to' is invalid as uri-escaped addr-spec #{addr.dump}"
        end
      end

      true
    end