syntax_data: {"ast_node_type":"other","tokens":[{"end":58,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // highest cycle head to the goal is the same.
context_before:             // A provisional cache entry is only valid if the current path from its
context_after:             if path_from_head == Self::cycle_path_kind(&self.stack, step_kind_from_parent, head) {