syntax_data: {"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"infcx.tcx.impl_trait_ref(source_impl).unwrap().instantiate(infcx.tcx,"}]}
source_snippet:         infcx.tcx.impl_trait_ref(source_impl).unwrap().instantiate(infcx.tcx, source_args);
context_before:     let source_trait_ref =