Add missing ABC for Metric (open-telemetry#391)

Fix open-telemetry#390
nstawski · Jan 31, 2020 · 27f04b6 · 27f04b6
1 parent 682ecc2
commit 27f04b6
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/opentelemetry-api/src/opentelemetry/metrics/__init__.py b/opentelemetry-api/src/opentelemetry/metrics/__init__.py
@@ -87,13 +87,14 @@ class DefaultLabelSet(LabelSet):
     """
 
 
-class Metric:
+class Metric(abc.ABC):
     """Base class for various types of metrics.
 
     Metric class that inherit from this class are specialized with the type of
     handle that the metric holds.
     """
 
+    @abc.abstractmethod
     def get_handle(self, label_set: LabelSet) -> "object":
         """Gets a handle, used for repeated-use of metrics instruments.