public void setKey(String key) {
        this.key = key;
    }
<p>
The key in a key-value pair. The key must be must be no longer than 128 Unicode characters. The key must be
unique for the resource to which it applies.
</p>

@param key
       The key in a key-value pair. The key must be must be no longer than 128 Unicode characters. The key must
       be unique for the resource to which it applies.
aws-java-sdk-cloudtrail/src/main/java/com/amazonaws/services/cloudtrail/model/Tag.java