syntax_data: {"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // `A, E, D, C, B` -- i.e., all the participants apart
context_before:             // the stack is the final `A`, then this will iterate over
context_after:             // from the cycle head. We mark them as participating in a