def METHOD_NAME(self, p):
    """ The exact solution 
    Parameters
    ---------
    p : 
    Examples
    -------
    p = np.array([0, 1], dtype=np.float)
    p = np.array([[0, 1], [0.5, 0.5]], dtype=np.float)
    """
    x = p[..., 0]
    y = p[..., 1]
    val = x*y 
    return val # val.shape == x.shape