vararg caCerts: X509Certificate,
) : TrustRootIndex {
  private val subjectToCaCerts: Map<X500Principal, Set<X509Certificate>>

  init {
    val map = mutableMapOf<X500Principal, MutableSet<X509Certificate>>()
    for (caCert in caCerts) {
      map.getOrPut(caCert.subjectX500Principal) { mutableSetOf() }.add(caCert)
    }
    this.subjectToCaCerts = map
  }