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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_system_application_data_directory():
 """ Returns the system Application data directory. Examples directories:: - 'C:\\Users\\$USER\\AppData\\Roaming' on Windows 7. - 'C:\\Documents and Settings\\$USER\\Application Data' on Windows XP. - '/Users/$USER/Library/Preferences' on Mac Os X. - '/home/$USER' on Linux. :return: User Application data directory. :rtype: unicode """


    if platform.system() == "Windows" or platform.system() == "Microsoft":
        environment = Environment("APPDATA")
        return environment.get_value()
    elif platform.system() == "Darwin":
        environment = Environment("HOME")
        return os.path.join(environment.get_value(), "Library", "Preferences")
    elif platform.system() == "Linux":
        environment = Environment("HOME")
        return environment.get_value()