Constant RPC_FAILURE_JSON 

pub const RPC_FAILURE_JSON: &str = "{\n  \"jsonrpc\": \"2.0\",\n  \"id\": \"connect-1\",\n  \"error\": {\n    \"code\": -32000,\n    \"message\": \"Device unavailable\",\n    \"data\": {\n      \"code\": \"device_unavailable\",\n      \"message\": \"Device android-emulator-5554 is unavailable\",\n      \"retryable\": true,\n      \"details\": {\n        \"deviceId\": \"android-emulator-5554\",\n        \"reason\": \"offline\"\n      }\n    }\n  }\n}\n";

Canonical JSON-RPC failure fixture.