@java.lang.Override
    public boolean hasExpireTime() {
      return expirationCase_ == 2;
    }
<pre>
Desired expiration time of the access token. This value must
be at most 24 hours in the future. If a value is not specified, the
token's expiration time will be set to a default value of 1 hour in the
future.
</pre>

<code>.google.protobuf.Timestamp expire_time = 2;</code>

@return Whether the expireTime field is set.
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/GenerateAccessTokenRequest.java