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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 auto_install(self):
 """ Whether automatic installation of missing system packages is enabled. :data:`True` if automatic installation of missing system packages is enabled, :data:`False` if it is disabled, :data:`None` otherwise (in this case the user will be prompted at the appropriate time). - Environment variable: ``$PIP_ACCEL_AUTO_INSTALL`` (refer to :func:`~humanfriendly.coerce_boolean()` for details on how the value of the environment variable is interpreted) - Configuration option: ``auto-install`` (also parsed using :func:`~humanfriendly.coerce_boolean()`) - Default: :data:`None` """

        value = self.get(property_name='auto_install',
                         environment_variable='PIP_ACCEL_AUTO_INSTALL',
                         configuration_option='auto-install')
        if value is not None:
            return coerce_boolean(value)