in lib/nano.js [575:587]
function replicateDb (source, target, opts0, callback0) {
const { opts, callback } = getCallback(opts0, callback0)
if (missing(source, target)) {
return callbackOrRejectError(callback)
}
// _replicate
opts.source = _serializeAsUrl(source)
opts.target = _serializeAsUrl(target)
return relax({ db: '_replicate', body: opts, method: 'POST' }, callback)
}