syntax_data: {"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"ImplSource,"}]}
source_snippet:     ImplSource, Obligation, ObligationCause, ObligationCtxt, ScrubbedTraitError, SelectionContext,
context_before: use rustc_trait_selection::traits::{
context_after:     SelectionError,