encode method
Implementation
Map<String, Object?> encode() => {
'visual_id': visualId.toTfJson(),
if (actions != null) 'actions': [for (final e in actions!) e.encode()],
'chart_configuration': ?chartConfiguration?.encode(),
'conditional_formatting': ?conditionalFormatting?.encode(),
'subtitle': ?subtitle?.encode(),
'title': ?title?.encode(),
};