@java.lang.Override
    public boolean hasTtl() {
      return expirationCase_ == 3;
    }
<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 Whether the ttl field is set.
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/GenerateAccessTokenRequest.java