Gets the parent section for the given section. The parent section is
the section that contains this section. A special case are sections of
type #GTK_CSS_SECTION_DOCUMENT. Their parent will either be null
if they are the original CSS document that was loaded by
gtk.css_provider.CssProvider.loadFromFile or a section of type
#GTK_CSS_SECTION_IMPORT if it was loaded with an import rule from
a different file.
Gets the parent section for the given section. The parent section is the section that contains this section. A special case are sections of type #GTK_CSS_SECTION_DOCUMENT. Their parent will either be null if they are the original CSS document that was loaded by gtk.css_provider.CssProvider.loadFromFile or a section of type #GTK_CSS_SECTION_IMPORT if it was loaded with an import rule from a different file.