@dispatch(DiagonalGaussian, kernels.Product, InducingPoints, kernels.Product, InducingPoints)
@quadrature_fallback
def _expectation(p, kern1, feat1, kern2, feat2):
if feat1 != feat2:
raise NotImplementedError("Different features are not supported")
if kern1 != kern2:
raise NotImplementedError("Calculating the expectation over two different Product kernels is not supported")
kern = kern1
feat = feat1
if not kern.on_separate_dimensions:
raise NotImplementedError("Product currently needs to be defined on separate dimensions.") // pragma: no cover
with tf.control_dependencies([