public Builder mergeExpirationTime(com.google.protobuf.Timestamp value) {
      if (expirationTimeBuilder_ == null) {
        if (((bitField0_ & 0x00000002) != 0)
            && expirationTime_ != null
            && expirationTime_ != com.google.protobuf.Timestamp.getDefaultInstance()) {
          getExpirationTimeBuilder().mergeFrom(value);
        } else {
          expirationTime_ = value;
        }
      } else {
        expirationTimeBuilder_.mergeFrom(value);
      }
      if (expirationTime_ != null) {
        bitField0_ |= 0x00000002;
        onChanged();
      }
      return this;
    }
<pre>
The expiration time of the token.
</pre>

<code>.google.protobuf.Timestamp expiration_time = 2;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/GenerateStreamHlsTokenResponse.java