@Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append("{");
        if (getTopic() != null)
            sb.append("Topic: ").append(getTopic()).append(",");
        if (getPayloadSize() != null)
            sb.append("PayloadSize: ").append(getPayloadSize()).append(",");
        if (getQos() != null)
            sb.append("Qos: ").append(getQos()).append(",");
        if (getLastModifiedTime() != null)
            sb.append("LastModifiedTime: ").append(getLastModifiedTime());
        sb.append("}");
        return sb.toString();
    }
Returns a string representation of this object. This is useful for testing and debugging. Sensitive data will be
redacted from this string using a placeholder value.

@return A string representation of this object.

@see java.lang.Object#toString()
aws-java-sdk-iot/src/main/java/com/amazonaws/services/iotdata/model/RetainedMessageSummary.java