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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_deploy_config(deploy_filename, config=None):
    '''
    Loads any local config overrides in the deploy file.
    '''

    if not config:
        config = Config()

    if not deploy_filename:
        return

    if path.exists(deploy_filename):
        extract_file_config(deploy_filename, config)

    return config