“…The expressions of these off-shell quantities, namely the"gravitational blocks", [4], were conjectured and proved to reproduce the corresponding observables, e.g., the Bekenstein-Hawking entropies, central charges, and free energies. Later, the gravitational blocks for solutions with orbifold singularities, i.e., spindle, were proposed, [5,6], and proved to calculate the duals of partition functions, [7,8,9,10,11,12]. See [13,14] also for an approach from string and M-theory.…”