public static IDCollection Select <TResult>(this IDCollection source, Func <KeyValuePair <string, int>, TResult> selector)
 {
     return(source);
 }
 public static IDCollection Cast <TResult>(this IDCollection source)
 {
     return(source);
 }
 public static IDCollection Where(this IDCollection source, Func <KeyValuePair <string, int>, bool> selector)
 {
     return(source);
 }