(mongodb >=1.15.0)
MongoDB\Driver\ClientEncryption::addKeyAltName — Adds an alternate name to a key document
$keyId, string $keyAltName): ?objectAdds keyAltName to the set of alternate names for the key document with the given UUID keyId.
keyIdA MongoDB\BSON\Binary instance with subtype 4 (UUID) identifying the key document.
keyAltNameAlternate name to add to the key document.
Returns the previous version of the key document, or null if no document matched.