context_shape(msg_ok, heartbeat, 0).
context_shape(msg_ok, source, 1).
context_shape(msg_ok, temperature, 2).
context_shape(msg_ok, gps, 3).
context_shape(msg_ok, signature, 4).
context_shape(msg_bad, heartbeat, 0).
context_shape(msg_bad, source, 1).
context_shape(msg_bad, temperature, 2).
context_shape(msg_bad, gps, 2).
context_shape(msg_bad, tampered, 1).
schema_violation(msg_bad, gps, 2).
schema_violation(msg_bad, tampered, 1).