def extend(self, axis, delta, npoints):
        if not delta:
            raise ValueError('delta must be non-zero')
        if npoints < 1:
            raise ValueError('npoints must be >= 1')
        i = len(self.shape)
        if i == 3:
            if axis not in ('i', 'j', 'k'):
                raise ValueError('axis must be i, j, or k')
            return self._extend_3d(axis, delta, npoints)
        elif i == 2:
            if axis not in ('i', 'j'):
                raise ValueError('axis must be i or j')
            return self._extend_2d(axis, delta, npoints)
        elif i == 1:
            if axis != 'i':
                raise ValueError('axis must be i')
            return self._extend_1d(delta, npoints)
        else:
            raise RuntimeError('FlowSolution is empty!')
Construct a new :class:`FlowSolution` by replication.
dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.lib/src/openmdao/lib/datatypes/domain/flow.py/FlowSolution.extend