@java.lang.Override
  public com.google.protobuf.Duration getTtl() {
    if (expirationCase_ == 3) {
      return (com.google.protobuf.Duration) expiration_;
    }
    return com.google.protobuf.Duration.getDefaultInstance();
  }
<pre>
Desired lifetime duration of the access token. This value must
be at most 24 hours. If a value is not specified, the token's lifetime
will be set to a default value of 1 hour.
</pre>

<code>.google.protobuf.Duration ttl = 3;</code>

@return The ttl.
java-workstations/proto-google-cloud-workstations-v1beta/src/main/java/com/google/cloud/workstations/v1beta/GenerateAccessTokenRequest.java