syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"ty::Placeholder(placeholder)"}]}
source_snippet:             ty::Placeholder(placeholder) => placeholder.print(self)?,
context_before:             ty::Alias(ty::Projection | ty::Inherent | ty::Free, ref data) => data.print(self)?,
context_after:             ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => {