boot_se                 Bootstrap Standard Errors (experimental)
center                  Automatically grand-mean or group-mean center a
                        fitted object
design_effect           Design Effect
hausman                 Hausman Test (experimental)
hsb                     HSB: High School and Beyond Data
icc                     Intraclass Correlation (ICC)
ncv_tests               Non-constant Variance Tests at Level-1
                        (experimental)
plausible_values        Plausible Values Range / Random Effect
                        Confidence Intervals
r2_cor                  Pseudo R-squared: Squared correlation between
                        predicted and observed values
r2_pve                  Proportion of variance explained
reliability             Calculate reliability coefficients for random
                        effects
robust_se               Robust Standard Errors
taucov                  Tau Covariance
