Incorporate existing knowledge about the likelihood
LF_base; see that page for documentation on likelihood factors in general.
character, the name of the factor. Should match a node name in the nodes specified by
A function that takes a sl3 regression task and returns true conditional means
A function that takes a sl3 regression task and returns true conditional densities
Not currently used.
character, either "density", for conditional density or, "mean" for conditional mean