createRuleset method
Creates a new Ruleset from the given RulesFile.
file - Rules file to include in the new Ruleset.
Returns a future that fulfills with the newly created Ruleset.
Implementation
Future<Ruleset> createRuleset(RulesFile file) async {
final ruleset = RulesetContent(source: RulesetSource(files: [file]));
final rulesetResponse = await _requestHandler.createRuleset(ruleset);
return Ruleset._fromResponse(rulesetResponse);
}