code: private static void encodeCopy(ByteBuf out, int offset, int length) {
          while (length >= 68) {
              encodeCopyWithOffset(out, offset, 64);
              length -= 64;
          }
  
          if (length > 64) {
              encodeCopyWithOffset(out, offset, 60);
              length -= 60;
          }
  
          encodeCopyWithOffset(out, offset, length);
      }
docs: Encodes a series of copies, each at most 64 bytes in length.
  
  @param out The output buffer to write the copy pointer to
  @param offset The offset at which the original instance lies
  @param length The length of the original instance