syntax_data: {"ast_node_type":"variable","tokens":[{"end":52,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:             if let Some(arg_hir_id) = param.hir_id {
context_before:             let span = pat.span;
context_after:                 self.set_correct_source_scope_for_arg(arg_hir_id, original_source_scope, span);