code: function _msb(word) {
    word |= word >> 1;
    word |= word >> 2;
    word |= word >> 4;
    word |= word >> 8;
    word |= word >> 16;
    word = (word >> 1) + 1;
    return multiplyDeBruijnBitPosition[(word * 0x077CB531) >>> 27];
  }
docs: Returns the least signifcant bit, or 0 if none set, so a prior check to see if the word > 0 is required
  @param word the current array
  @returns {number} the index of the most significant bit in the current array
  @private