public String getDocumentVersion() {
        return this.documentVersion;
    }
<p>
The Amazon Web Services Systems Manager document (SSM document) version to use in the request. You can specify
<code>$DEFAULT</code>, <code>$LATEST</code>, or a specific version number. If you run commands by using the
Amazon Web Services CLI, then you must escape the first two options by using a backslash. If you specify a
version number, then you don't need to use the backslash. For example:
</p>
<p>
<code>--document-version "\$DEFAULT"</code>
</p>
<p>
<code>--document-version "\$LATEST"</code>
</p>
<p>
<code>--document-version "3"</code>
</p>

@return The Amazon Web Services Systems Manager document (SSM document) version to use in the request. You can
        specify <code>$DEFAULT</code>, <code>$LATEST</code>, or a specific version number. If you run commands by
        using the Amazon Web Services CLI, then you must escape the first two options by using a backslash. If
        you specify a version number, then you don't need to use the backslash. For example:</p>
        <p>
        <code>--document-version "\$DEFAULT"</code>
        </p>
        <p>
        <code>--document-version "\$LATEST"</code>
        </p>
        <p>
        <code>--document-version "3"</code>
aws-java-sdk-ssm/src/main/java/com/amazonaws/services/simplesystemsmanagement/model/MaintenanceWindowRunCommandParameters.java