code: public int numChars() {
  		ensureMaterialized();
  		if (inFirstSegment()) {
  			int len = 0;
  			for (int i = 0; i < sizeInBytes; i += numBytesForFirstByte(getByteOneSegment(i))) {
  				len++;
  			}
  			return len;
  		} else {
  			return numCharsSlow();
  		}
  	}
docs: Returns the number of code points in it.