static ResponseLogLevelMapper of(HttpStatus status, LogLevel logLevel) {
        requireNonNull(status, "status");
        requireNonNull(logLevel, "logLevel");
        return log -> log.responseStatus() == status ? logLevel : null;
    }
Creates a new {@link ResponseLogLevelMapper} which returns the specified {@link LogLevel} if the given
{@link RequestLog#responseStatus()} is equal to the specified {@link HttpStatus}.
core/src/main/java/com/linecorp/armeria/common/logging/ResponseLogLevelMapper.java