syntax_data: {"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"tcx.own_existential_vtable_entries(vtable_principal.def_id).len();"}]}
source_snippet:                         tcx.own_existential_vtable_entries(vtable_principal.def_id).len();
context_before:                     vptr_offset +=
context_after:                     if ty::ExistentialTraitRef::erase_self_ty(tcx, vtable_principal)