syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":".then(Tree::byte(0x00))"}]}
source_snippet:                 .then(Tree::byte(0x00))
context_before:             let layout: Tree<Def, !, !> = Tree::def(Def::NoSafetyInvariants)
context_after:                 .then(Tree::def(Def::HasSafetyInvariants));