putExtra method
Aims to handle type information for extra data attached encodes type information as string, passed through PlatformChannel, and finally gets unpacked in platform specific code ( Kotlin )
TypedExtra class holds predefined constants ( type information ), consider using those
Implementation
putExtra(String extra, dynamic data, {String? type}) {
this._extra[extra] = data;
if (type != null) this._typeInfo[extra] = type;
}