a string identifying a particular type of icon, or NULL to list all icons. [allow-none]
a GList list holding the names of all the icons in the theme. You must first free each element in the list with g_free(), then free the list itself with g_list_free(). [element-type utf8][transfer full]
Lists the icons in the current icon theme. Only a subset of the icons can be listed by providing a context string. The set of values for the context string is system dependent, but will typically include such values as "Applications" and "MimeTypes". Since 2.4