getMap method
Implementation
Map<String, String> getMap(String key) => {
"key": key,
if (maxResults != null) QueryParameter.maxResults.name: "$maxResults",
if (onBehalfOfContentOwner != null)
QueryParameter.onBehalfOfContentOwner.name: onBehalfOfContentOwner!,
if (pageToken != null) QueryParameter.pageToken.name: pageToken!,
if (regionCode != null) QueryParameter.regionCode.name: regionCode!,
};