syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // _4 = &mut (_1.0: i32);  // this is handling `(mut x, 1)` case
context_before:             // StorageLive(_4);        // _4 is `x`
context_after:             // _4 = &mut (_1.1: i32);  // this is handling `(2, mut x)` case