Bootstrap Resampling for Multilevel Models // Functions for bootstrapping with multilevel data and models (and mixed-effect models). It implements multiple bootstrap methods under the parametric, residual, and case bootstrap categories, as discussed in Van der Leeden, Meijer, and Busing (2008) doi:10.1007/978-0-387-73186-5_11 and Carpenter, Goldstein, and Rasbash (2003) doi:10.1111/1467-9876.00415. Currently it supports fitted objects from the 'lme4' package.