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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 check_connection (self):
 """ Try to open the local file. Under NT systems the case sensitivity is checked. """

        if (self.parent_url is not None and
           not self.parent_url.startswith(u"file:")):
            msg = _("local files are only checked without parent URL or when the parent URL is also a file")
            raise LinkCheckerError(msg)
        if self.is_directory():
            self.set_result(_("directory"))
        else:
            url = fileutil.pathencode(self.url)
            self.url_connection = urlopen(url)
            self.check_case_sensitivity()