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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 _checkCopyright(self, text, node):
 """ Check whether the module has copyright header. @param text: codes of the module @param node: node of the module """

        if not re.search(br"%s\s*\n\s*%s" % self.commentsCopyright, text):
            self.add_message('W9001', node=node)