{"ast_node_type":"function","tokens":[{"end":83,"kind":"keyword","start":0,"text":"fn"}]}
    fn from_iter<I: IntoIterator<Item = DropckConstraint<'tcx>>>(iter: I) -> Self {
impl<'tcx> FromIterator<DropckConstraint<'tcx>> for DropckConstraint<'tcx> {
        let mut result = Self::empty();