openFile method
Open the file represented by task
or filePath
using the application
available on the platform.
mimeType
may override the mimetype derived from the file extension,
though implementation depends on the platform and may not always work.
Returns true if an application was launched successfully
Implementation
Future<bool> openFile({Task? task, String? filePath, String? mimeType}) {
assert(task != null || filePath != null, 'Task or filePath must be set');
assert(!(task != null && filePath != null),
'Either task or filePath must be set, not both');
return _downloader.openFile(task, filePath, mimeType);
}