Application
Creates a new AdwApplication.
If application_id is not NULL, then it must be valid. See func@Gio.Application.id_is_valid.
If no application ID is given then some features (most notably application uniqueness) will be disabled.
Return
the newly created AdwApplication
Parameters
applicationId
The application ID
flags
The application flags
constructor(pointer: <Error class: unknown class><<Error class: unknown class>>)