def METHOD_NAME(self):
    """
    Return True if ``self`` is a hypersurface, i.e. an object of the type
    :class:`ProjectiveHypersurface` or :class:`AffineHypersurface`.
    EXAMPLES::
        sage: from sage.schemes.generic.hypersurface import is_Hypersurface
        sage: R.<x, y, z> = ZZ[]
        sage: H = ProjectiveHypersurface(x*z + y^2)
        sage: is_Hypersurface(H)
        True
    ::
        sage: H = AffineHypersurface(x*z + y^2)
        sage: is_Hypersurface(H)
        True
    ::
        sage: H = ProjectiveSpace(QQ, 5)
        sage: is_Hypersurface(H)
        False
    """
    return isinstance(self, (ProjectiveHypersurface, AffineHypersurface))