ess.TraceWin.envDiag return also parameter NUM for DIAG id number

ess/TraceWin.py

@@ -1248,6 +1248,8 @@ class envDiag():
         Returns a list containing the given parameter from all DIAGS,
         ordered by the location of the DIAGs
         '''
+        if parameter == 'NUM':
+            return self._elementList[:]
         ret = []
         for key in self._elementList:
             ret.append(self.elements[key][parameter])