leave1out is generic. For suitable model objects, it repeatedly fits the model, leaving out one observation at a time.leave1out(x, ...)"rma.uni", "rma.mh", or "rma.peto"."rma.uni", "rma.mh", and "rma.peto" with the leave1out function. Accordingly, the corresponding methods are called leave1out.rma.uni, leave1out.rma.mh, and leave1out.rma.peto. See the documentation for those functions for more details.leave1out.rma.uni, leave1out.rma.mh, leave1out.rma.peto