code: public boolean startsWith(CharSequence prefix, int startIndex) {
  		final char[] thisChars = this.value;
  		final int pLen = this.len;
  		final int sLen = prefix.length();
  	
  		if ((startIndex < 0) || (startIndex > pLen - sLen)) {
  			return false;
  		}
  		
  		int sPos = 0;
  		while (sPos < sLen) {
  			if (thisChars[startIndex++] != prefix.charAt(sPos++)) {
  				return false;
  			}
  		}
  		return true;
  	}
docs: Checks whether the substring, starting at the specified index, starts with the given prefix string.
  
  @param prefix The prefix character sequence.
  @param startIndex The position to start checking for the prefix.
  
  @return True, if this StringValue substring, starting at position <code>startIndex</code> has <code>prefix</code>
  as its prefix.