code: public ArrayList<String> getColumns() {
  		ArrayList<String> columns = new ArrayList<String>();
  		for (String col : columnLookup.keySet()) {
  			HeaderInfo hi = columnLookup.get(col);
  			if (!hi.isHide()) {
  				columns.add(col);
  			}
  		}
  		return columns;
  	}
docs: Get the list of column names. Does not include hidden columns
  
  @return