ensureDevDependencies method
Ensures that all provided packages exist in the development
dependencies.
Each map key represents a package name and its value represents the dependency version.
Implementation
Future<void> ensureDevDependencies(Map<String, String> packages) async {
await _ensureLoaded();
for (final entry in packages.entries) {
await ensureDevDependency(entry.key, version: entry.value);
}
}