From a83533aa8166ca2414137cdfc3125a53ee3697ec Mon Sep 17 00:00:00 2001
From: Jan Kwakkel <j.h.kwakkel@tudelft.nl>
Date: Mon, 30 May 2022 19:16:14 +0200
Subject: [PATCH] instantiating an Evaluator without one or more AbstractModel
 instances now raises a type error

---
 ema_workbench/em_framework/evaluators.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/ema_workbench/em_framework/evaluators.py b/ema_workbench/em_framework/evaluators.py
index 2be9bf350..51d6e0334 100644
--- a/ema_workbench/em_framework/evaluators.py
+++ b/ema_workbench/em_framework/evaluators.py
@@ -111,6 +111,11 @@ def __init__(self, msis):
 
         if isinstance(msis, AbstractModel):
             msis = [msis]
+        else:
+            for entry in msis:
+                if not isinstance(entry, AbstractModel):
+                    raise TypeError((f"{entry} should be an AbstractModel "
+                                     f"instance but is a {entry.__class__} instance"))
 
         self._msis = msis
         self.callback = None
@@ -274,7 +279,6 @@ def robust_optimize(
 
 
 class SequentialEvaluator(BaseEvaluator):
-
     def initialize(self):
         pass
 
@@ -790,4 +794,4 @@ def robust_optimize(
         convergence_freq,
         logging_freq,
         **kwargs,
-    )
+    )
\ No newline at end of file