Name of the GtkSourceMark, can be NULL when not using a name
is used to classify marks according to common characteristics (e.g. all the marks representing a bookmark could belong to the "bookmark" category, or all the marks representing a compilation error could belong to "error" category).
ConstructionException GTK+ fails to create the object.
Creates a text mark. Add it to a buffer using gtk_text_buffer_add_mark(). If name is NULL, the mark is anonymous; otherwise, the mark can be retrieved by name using gtk_text_buffer_get_mark(). Normally marks are created using the utility function gtk_source_buffer_create_mark(). Since 2.2