DataGridColumn add(
    in DOMString id,
    in DOMString label,
    in DOMString type,
    in boolean primary,
    in unsigned short sortable); 

void clear(); 

DataGridColumn item(
    in unsigned long index); 

void move(
    in DataGridColumn column,
    in unsigned long index); 

void remove(
    in DataGridColumn column); 

readonly attribute unsigned long length; 

readonly attribute DataGridColumn primaryColumn; 

readonly attribute DataGridColumn sortColumn;