Could you please add either as an inline comment or in the docstring what you explained in the description of this PR, namely:

```
the :method:log-likelihood of :class:EmpiricalCovariance returns a normalized, biased, and scaled version of the log-likelihood, renamed it empirical expected log-likelihood (accounting for the normalization), rescaled it, and added its constants, so universal comparison is possible (beyond this software package)
```