Gst.Structure.prototype.map_in_place

function map_in_place(func:Gst.StructureMapFunc):Boolean {
    // Gjs wrapper for gst_structure_map_in_place()
}

Calls the provided function once for each field in the Gst.Structure. In contrast to Gst.Structure.prototype.foreach, the function may modify but not delete the fields. The structure must be mutable.