public String getKey() {
        return this.key;
    }
<p>
The key that specifies the tag that you're using to filter the search results. It must be in the following
format: <code>Tags.&lt;key&gt;</code>.
</p>

@return The key that specifies the tag that you're using to filter the search results. It must be in the
        following format: <code>Tags.&lt;key&gt;</code>.
aws-java-sdk-sagemaker/src/main/java/com/amazonaws/services/sagemaker/model/VisibilityConditions.java