syntax_data: {"ast_node_type":"import","tokens":[{"end":74,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! `InferCtxt`. To use the data from evaluation we therefore canonicalize
context_before: //! use proof trees without somehow "lifting up" data local to the current
context_after: //! it and store it as a [CanonicalState].