public GetExtensionRequest withVersionNumber(Integer versionNumber) {
        setVersionNumber(versionNumber);
        return this;
    }
<p>
The extension version number. If no version number was defined, AppConfig uses the highest version.
</p>

@param versionNumber
       The extension version number. If no version number was defined, AppConfig uses the highest version.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-appconfig/src/main/java/com/amazonaws/services/appconfig/model/GetExtensionRequest.java