count bytes of
an image. It will return TRUE if the data was loaded successfully,
and FALSE if an error occurred. In the latter case, the loader
will be closed, and will not accept further writes. If FALSE is
returned, error will be set to an error from the GDK_PIXBUF_ERROR
or G_FILE_ERROR domains.gdkPixbufLoaderWrite(object, buf, .errwarn = TRUE)objectGdkPixbufLoader] A pixbuf loader.bufTRUE if the write was successful, or FALSE if the loader
cannot parse the buffer.errorGError] return location for errors