protected static boolean isCircuitFault(ApiResponse response, CircuitBreakerConfigBean config) {
        int code = response.getCode();
        for (String codePattern : config.getErrorCodes()) {
            if (isMatch(code, codePattern)) {
                return true;
            }
        }
        return false;
    }
Returns true if the API response represents a circuit fault.  This depends on
the return code from the back end API as well as the configuration of the policy.
@param response
@param config
plugins/circuit-breaker-policy/src/main/java/io/apiman/plugins/circuit_breaker/CircuitBreakerPolicy.java