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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 isUserCert(self, name):
        '''
        Checks if a user certificate exists.

        Args:
            name (str): The name of the user keypair.

        Examples:
            Check if the user cert "myuser" exists:

                exists = cdir.isUserCert('myuser')

        Returns:
            bool: True if the certificate is present, False otherwise.
        '''
        crtpath = self._getPathJoin('users', '%s.crt' % name)
        return os.path.isfile(crtpath)