class_docstr: A mapping that will load all pairs of key values at the first access (either by indexing, requestions keys, values,
  etc.)
  
  Args:
      mapping: The mapping to load.
class_docstr_tok: ["A","mapping","that","will","load","all","pairs","of","key","values","at","the","first","access","(","either","by","indexing",",","requestions","keys",",","values",",","etc",".",")","Args",":","mapping",":","The","mapping","to","load","."]
code: def __iter__(self):
      self._initialize()
      return iter(self._data)
  
imports: import importlib
  import re
  from collections import OrderedDict
  from typing import List, Union
  from fastNLP.transformers.torch.configuration_utils import PretrainedConfig
  from fastNLP.transformers.torch.file_utils import CONFIG_NAME
  from fastNLP.core.log import logger
label_desc: Use image node_id 7 for calling the _LazyLoadAllMappings obj's underlying member method code with example usage: obj.__iter__() and returns: iter