public Operation withCreatedAt(java.util.Date createdAt) {
        setCreatedAt(createdAt);
        return this;
    }
<p>
The timestamp when the operation was initialized (<code>1479816991.349</code>).
</p>

@param createdAt
       The timestamp when the operation was initialized (<code>1479816991.349</code>).
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-lightsail/src/main/java/com/amazonaws/services/lightsail/model/Operation.java