in qf.go [152:157]
func (qf *Filter) allocStorage() { qf.filter = qf.allocfn(3+bitsPerWord-qf.qBits, qf.size) if qf.config.BitsOfStoragePerEntry > 0 { qf.storage = qf.allocfn(qf.config.BitsOfStoragePerEntry, qf.size) } }