Returns an SDMOData Entry with the specified key if it is stored in SDMCache or null otherwise. 
      Syntax
         
         
            public 
            ISDMODataEntry  
            getSDMODataEntry
            (
            String 
            key
            )
         
      
      Parameters
         
         
            - 
               key – 
               key of the entry to be searched
            
 
         
       
      Returns
         SDMODataEntry or null
      Exceptions
         
         
            - 
               IllegalArgumentException – 
               if the argument is null.