syntax_data: {"ast_node_type":"other","tokens":[{"end":59,"kind":"keyword","start":0,"text":".map_bound(|witness|"}]}
source_snippet:                 .map_bound(|witness| AutoImplConstituents {
context_before:                 .instantiate(self.infcx.tcx, args)
context_after:                     types: witness.types.to_vec(),