{"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"UnsizeCast"}]}
    UnsizeCast { source_ty: Ty<'tcx>, target_ty: Ty<'tcx> },
    /// Unsizing casts might require vtables, so we have to record them.
    /// A closure that is coerced to a function pointer.