The names of the term's columns, such as ["(Intercept)", "Days"].
Their correlation matrix (array of rows; 1 on the diagonal).
The grouping factor's name, such as "Subject" or "cask:batch".
The standard deviations of the random effects, one per column.
The variance and correlation parameters of a random-effects term in a LmerResult: one entry of R's
VarCorr().