syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"report_unreachable_pattern(cx,"}]}
source_snippet:                     report_unreachable_pattern(cx, arm.arm_data, pat, &explanation, None)
context_before:                 for (pat, explanation) in redundant_subpats {
context_after:                 }