c# - Design issue with Generics -

I have a class with two public methods:

  class first class { Public IERTTE Gatety (string by user name); Public IERTTE Gatementi (Entry Bye UserID); }   
 I want to wrap those methods with normal squared which looks like this:   class EntityHandler & lt; T & gt; {The Public Inventory Recovery Entity (T Users) • Return the first class. GateInty (Usergame)}}   
 will not work at all because the type of  userParam  is unknown this point . How can I verify that  T  is  int  or  string  and then the appropriate  getEntity ()  method Pass successfully from?   
 
 
 I do not see any requirement for  EntityHandler  to be normal  
  Class EntityHandler {First Class First Class = New First Class (); Public IEntity RetrieveEntity (int user) {return firstClass.GetEntity (userParam); } Public IEntity RetrieveEntity (string usersperm) {return firstClass.GetEntity (userParam); }}