static reverseBits_(x) {
    let val = x;
    let reversed = 0;
    for (let i = 0; i < 32; i++) {
      reversed |= val & 1;
      if (i == 31) {
        break;
      }
      reversed <<= 1;
      val >>= 1;
    }
    return reversed;
  }
Reverse a number bit to bit
@param {number} x
@return {number}
@private