The value will have been initialized to the GType the value should be
provided in. This given GType does not need to be listed in the formats
returned by gdk.content_provider.ContentProvider.refFormats. However, if the
given GType is not supported, this operation can fail and
gio.types.IOErrorEnum.NotSupported will be reported.
Gets the contents of provider stored in value.
The value will have been initialized to the GType the value should be provided in. This given GType does not need to be listed in the formats returned by gdk.content_provider.ContentProvider.refFormats. However, if the given GType is not supported, this operation can fail and gio.types.IOErrorEnum.NotSupported will be reported.