gtk:expander-label (object)

object -- a gtk:expander widget
label -- a string for the text of the label of the expander

The accessor for the label slot gets or sets the text from a label widget including any embedded underlines indicating mnemonics and Pango markup.

If the label text has not been set the return value will be nil. This will be the case if you create an empty button with the gtk:button-new function to use as a container.