syntax_data: {"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let mut dropline_transition_bb: Option<BasicBlock> = None;
context_before:         // Second state-loop yield for transition to dropline (when coroutine async drop started)
context_after:         let mut dropline_yield_bb: Option<BasicBlock> = None;