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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 yaml_load(stream):
 """Load YAML file using safe loader."""

    # Surprisingly, the CSafeLoader does not seem to be used by default.
    # Check whether the CSafeLoader is available and provide a log message
    # if it is not available.
    global _HAS_YAML_LIBRARY

    if _HAS_YAML_LIBRARY is None:
        _HAS_YAML_LIBRARY = hasattr(yaml, 'CSafeLoader')
        if not _HAS_YAML_LIBRARY:
            logger.warning('libyaml was not found! Please install libyaml to'
                           ' speed up loading the model files.')

    if _HAS_YAML_LIBRARY:
        loader = yaml.CSafeLoader(stream)
    else:
        loader = yaml.SafeLoader(stream)
    loader.add_constructor('tag:yaml.org,2002:float', float_constructor)
    return loader.get_data()