string containing both a certificate and PKCS #8-encoded private key.

    ```kotlin
    val heldCertificate = HeldCertificate.decode("""
        |-----BEGIN CERTIFICATE-----
        |MIIBYTCCAQegAwIBAgIBKjAKBggqhkjOPQQDAjApMRQwEgYDVQQLEwtlbmdpbmVl
        |cmluZzERMA8GA1UEAxMIY2FzaC5hcHAwHhcNNzAwMTAxMDAwMDA1WhcNNzAwMTAx

      var month = -1
      var year = -1
      val matcher = TIME_PATTERN.matcher(s)

      while (pos < limit) {
        val end = dateCharacterOffset(s, pos + 1, limit, true)
        matcher.region(pos, end)

        when {
          hour == -1 && matcher.usePattern(TIME_PATTERN).matches() -> {
            hour = matcher.group(1).toInt()
            minute = matcher.group(2).toInt()