syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"CanonicalVarKind::PlaceholderTy(placeholder)"}]}
source_snippet:             CanonicalVarKind::PlaceholderTy(placeholder) => placeholder.var().as_usize(),
context_before:             CanonicalVarKind::PlaceholderRegion(placeholder) => placeholder.var().as_usize(),
context_after:             CanonicalVarKind::PlaceholderConst(placeholder) => placeholder.var().as_usize(),