Question about avaliable operators

Hello maintainers,

I am trying to get certain matvecs via QBX. In particular, I need to evaluate the adjoint double layer potential and the hyper singular operator of a given kernel. I already see how via S and D in the documentation under symbolic operator representations I can get a single and double layer potential, but I don't understand what Sp, Spp, Dp, and Dpp are. Moreover, what I really need is:

$T(f)(x) : = \int_{\Gamma} dG(x,y)/dn(x) * f(y) dS_{y}$ and $H(f)(x) := -\int_{\Gamma} d^{2}G(x,y)/dn(x)dn(y) f(y) dS_{y}$. How. do I get these out o the QBX infrastructure present in this package?

(These can be found via normal FMM/HMatrix means as in [Bempp](http://bempp.com/handbook/api/boundary_operators.html), but I'd like to compare these methods against QBX if it is possible)