public Tag withKey(String key) {
        setKey(key);
        return this;
    }
<p>
Tag key. The key can't start with aws:.
</p>

@param key
       Tag key. The key can't start with aws:.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-storagegateway/src/main/java/com/amazonaws/services/storagegateway/model/Tag.java