code: public JKTableColumn getTableColumn(final int col, final boolean visibleIndex) {
  		int actualIndex;
  		if (visibleIndex) {
  			actualIndex = this.visibilityManager.getActualIndexFromVisibleIndex(col);
  		} else {
  			actualIndex = col;
  		}
  		return this.tableColumns.get(actualIndex);
  	}
docs: return NULL of col is out of bound.
  
  @param col          the col
  @param visibleIndex the visible index
  @return the table column