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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_requirements(self):
 """ Check if VPCS is available with the correct version. """


        path = self._vpcs_path()
        if not path:
            raise VPCSError("No path to a VPCS executable has been set")

        # This raise an error if ubridge is not available
        self.ubridge_path

        if not os.path.isfile(path):
            raise VPCSError("VPCS program '{}' is not accessible".format(path))

        if not os.access(path, os.X_OK):
            raise VPCSError("VPCS program '{}' is not executable".format(path))

        yield from self._check_vpcs_version()