class_docstr: 通过该 callback 来测试模型的训练是否基本正常；
class_docstr_tok: ["\u901a\u8fc7\u8be5","callback","\u6765\u6d4b\u8bd5\u6a21\u578b\u7684\u8bad\u7ec3\u662f\u5426\u57fa\u672c\u6b63\u5e38\uff1b"]
code: def __init__(self, loss_threshold: float):
      self.loss = None
      self.loss_threshold = loss_threshold
      self.loss_begin_value = None
  
imports: from fastNLP.core.callbacks.callback import Callback
label_desc: Use image node_id 1 to create a new RecordLossCallback object from inherited base classes: Callback with example: obj = RecordLossCallback(loss_threshold)