280                                       uint8_t *To, size_t ToSize) {  in CopyPartOf()  argument
282   size_t ToBeg = Rand(ToSize);  in CopyPartOf()
283   size_t CopySize = Rand(ToSize - ToBeg) + 1;  in CopyPartOf()
284   assert(ToBeg + CopySize <= ToSize);  in CopyPartOf()
289   return ToSize;  in CopyPartOf()
295                                         uint8_t *To, size_t ToSize,  in InsertPartOf()  argument
297   if (ToSize >= MaxToSize) return 0;  in InsertPartOf()
298   size_t AvailableSpace = MaxToSize - ToSize;  in InsertPartOf()
303   size_t ToInsertPos = Rand(ToSize + 1);  in InsertPartOf()
305   size_t TailSize = ToSize - ToInsertPos;  in InsertPartOf()
315   return ToSize + CopySize;  in InsertPartOf()