skipLeadingZeros_() {
    let i;
    for (i = 0; i < this.workingBitsAvailable_; ++i) {
      if ((this.workingWord_ & (0x80000000 >>> i)) !== 0) {
        // the first bit of working word is 1
        this.workingWord_ <<= i;
        this.workingBitsAvailable_ -= i;
        return i;
      }
    }

    // we exhausted workingWord and still have not found a 1
    this.loadWord_();
    return i + this.skipLeadingZeros_();
  }
Return the number of skip leading zeros

@return {number}
@private