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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 in_project_directory() -> bool: """ Returns whether or not the current working directory is a Cauldron project directory, which contains a cauldron.json file. """

    current_directory = os.path.realpath(os.curdir)
    project_path = os.path.join(current_directory, 'cauldron.json')
    return os.path.exists(project_path) and os.path.isfile(project_path)