private com.google.protobuf.SingleFieldBuilderV3<
            com.google.protobuf.Timestamp,
            com.google.protobuf.Timestamp.Builder,
            com.google.protobuf.TimestampOrBuilder>
        getExpireTimeFieldBuilder() {
      if (expireTimeBuilder_ == null) {
        expireTimeBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.protobuf.Timestamp,
                com.google.protobuf.Timestamp.Builder,
                com.google.protobuf.TimestampOrBuilder>(
                getExpireTime(), getParentForChildren(), isClean());
        expireTime_ = null;
      }
      return expireTimeBuilder_;
    }
<pre>
Time at which the generated token will expire.
</pre>

<code>.google.protobuf.Timestamp expire_time = 2;</code>
java-workstations/proto-google-cloud-workstations-v1/src/main/java/com/google/cloud/workstations/v1/GenerateAccessTokenResponse.java