fixup! Use helper function to find matching instance in dataset

metricflow/dataset/sql_dataset.py

@@ -122,27 +122,28 @@ def column_association_for_dimension(
 
         return column_associations_to_return[0]
 
-    def instance_for_time_dimension(self, time_dimension_spec: TimeDimensionSpec) -> TimeDimensionInstance:
-        """Given the name of the time dimension, return the instance associated with it in the data set."""
+    def instances_for_time_dimensions(
+        self, time_dimension_specs: Sequence[TimeDimensionSpec]
+    ) -> List[TimeDimensionInstance]:
+        """Return the instances associated with these specs in the data set."""
         matching_instances = 0
-        instance_to_return = None
+        instances_to_return: List[TimeDimensionInstance] = []
         for time_dimension_instance in self.instance_set.time_dimension_instances:
-            if time_dimension_instance.spec == time_dimension_spec:
-                instance_to_return = time_dimension_instance
+            if time_dimension_instance.spec in time_dimension_specs:
+                instances_to_return.append(time_dimension_instance)
                 matching_instances += 1
 
-        if matching_instances > 1:
+        if matching_instances != len(time_dimension_specs):
             raise RuntimeError(
-                f"More than one time dimension instance with spec {time_dimension_spec} in "
-                f"instance set: {self.instance_set}"
+                f"Unexpected number of time dimension instances found matching specs.\nSpecs: {time_dimension_specs}\n"
+                f"Instances: {matching_instances}"
             )
 
-        if not instance_to_return:
-            raise RuntimeError(
-                f"No time dimension instances with spec {time_dimension_spec} in instance set: {self.instance_set}"
-            )
+        return instances_to_return
 
-        return instance_to_return
+    def instance_for_time_dimension(self, time_dimension_spec: TimeDimensionSpec) -> TimeDimensionInstance:
+        """Given the name of the time dimension, return the instance associated with it in the data set."""
+        return self.instances_for_time_dimensions([time_dimension_spec])[0]
 
     def column_association_for_time_dimension(self, time_dimension_spec: TimeDimensionSpec) -> ColumnAssociation:
         """Given the name of the time dimension, return the set of columns associated with it in the data set."""