getThemesFromJson function
Finds the themes in the input json
Implementation
List<TokenTheme> getThemesFromJson(Map<String, dynamic> input) {
final sets = getSetsFromJson(input);
final themes = input['\$themes'] as List?;
if (themes == null || themes.isEmpty) return [];
return themes
.map((e) => TokenTheme.fromJson(e as Map<String, dynamic>, sets))
.toList();
}