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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def load_all(kls):
 """Force immediate load of all metadata"""

        # Force expansion of contents to lists because we invalidate the iterator
        for region_code, loader in list(kls._region_available.items()):
            if loader is not None:  # pragma no cover
                loader(region_code)
                kls._region_available[region_code] = None
        for country_code, loader in list(kls._country_code_available.items()):
            if loader is not None:
                loader(country_code)
                kls._country_code_available[region_code] = None