@classmethod
def _package_installed(cls, package_info):
    """
        Try to find out whether the specified package is installed or not.

        If the installed state cannot be determined with certainty we assume
        it's installed.

        Args:
            package_info (package_info.PackageInfo):
                The package to check.

        Returns:
            True or False

        """
    return cls.installed_states.get(package_info.status, True)
