code: public StringGrabber removeHead(int cnt) {
  		try {
  			sb.delete(0, cnt);
  		} catch (Exception e) {
  			e.printStackTrace();
  		}
  		return StringGrabber.this;
  	}
docs: remove N chars from head
  
  @see StringGrabber#carryHead()
  @param cnt
  count of chars
  @return