@Override
    public LogItem intercept(LogItem log) {
        if (reject(log)) {
            // Filter this log out.
            return null;
        }
        return log;
    }
{@inheritDoc}

@param log the original log
@return the original log if it is acceptable, or null if it should be filtered out
android/android_framework/base/src/main/java/com/elvishew/xlog/interceptor/AbstractFilterInterceptor.java