code: public static int varintSizeInBytes(long v) {
      if ((v & (0xffffffffffffffffL << 7)) == 0) return 1;
      if ((v & (0xffffffffffffffffL << 14)) == 0) return 2;
      if ((v & (0xffffffffffffffffL << 21)) == 0) return 3;
      if ((v & (0xffffffffffffffffL << 28)) == 0) return 4;
      if ((v & (0xffffffffffffffffL << 35)) == 0) return 5;
      if ((v & (0xffffffffffffffffL << 42)) == 0) return 6;
      if ((v & (0xffffffffffffffffL << 49)) == 0) return 7;
      if ((v & (0xffffffffffffffffL << 56)) == 0) return 8;
      if ((v & (0xffffffffffffffffL << 63)) == 0) return 9;
      return 10;
    }
docs: Like {@link #varintSizeInBytes(int)}, except for uint64.