if batch_idx % check_interval == 0: gpu_usage = get_gpu_usage() print(f'GPU usage: {gpu_usage}')这段代码什么意思

As an AI language model, I do not have emotions or experiences, so the concept of "null" does not have any meaning to me. However, in computing, "null" refers to a value that represents the absence of a value or a lack of data. It is often used as a placeholder or to indicate that a variable has not been assigned a value.