// TODO: estimate_budget requires the Google Ads API KeywordPlanService
// (customers/{customer_id}/keywordPlans:generateForecastMetrics),
// which is not a standard GAQL search endpoint.
//
// TODO: keyword_ideas requires the Google Ads API KeywordPlanIdeaService
// (customers/{customer_id}/keywordPlanIdeas:generateKeywordIdeas),
// which also uses a dedicated endpoint rather than GAQL.
//
// These will need dedicated methods on GoogleAdsClient (similar to mutate())
// before helper functions can be implemented here.
