'Compute a local interpolant over the last successful step.
Returns
sol : `DenseOutput`
Local interpolant over the last successful step.'

def dense_output(self):

    if (self.t_old is None):
        raise RuntimeError('Dense    output    is    available    after    a    successful    step    was    made.')
    if ((self.n == 0) or (self.t == self.t_old)):
        return ConstantDenseOutput(self.t_old, self.t, self.y)
    else:
        return self._dense_output_impl()
