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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 _get_dir(toml_config_setting, sawtooth_home_dir, windows_dir, default_dir):
 """Determines the directory path based on configuration. Arguments: toml_config_setting (str):
 The name of the config setting related to the directory which will appear in path.toml. sawtooth_home_dir (str):
 The directory under the SAWTOOTH_HOME environment variable. For example, for 'data' if the data directory is $SAWTOOTH_HOME/data. windows_dir (str):
 The windows path relative to the computed base directory. default_dir (str):
 The default path on Linux. Returns: directory (str):
 The path. """

    conf_file = os.path.join(_get_config_dir(), 'path.toml')
    if os.path.exists(conf_file):
        with open(conf_file) as fd:
            raw_config = fd.read()
        toml_config = toml.loads(raw_config)
        if toml_config_setting in toml_config:
            return toml_config[toml_config_setting]

    if 'SAWTOOTH_HOME' in os.environ:
        return os.path.join(os.environ['SAWTOOTH_HOME'], sawtooth_home_dir)

    if os.name == 'nt':
        base_dir = \
            os.path.dirname(os.path.dirname(os.path.abspath(sys.argv[0])))
        return os.path.join(base_dir, windows_dir)

    return default_dir