Add attribute check

newrelic/samplers/gc_data.py

@@ -1,4 +1,4 @@
 # Copyright 2010 New Relic, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -26,19 +26,22 @@
 
 @data_source_factory(name="Garbage Collector Metrics")
 class _GCDataSource:
     def __init__(self, settings, environ):
         self.gc_time_metrics = CustomMetrics()
         self.start_time = 0.0
         self.previous_stats = {}
         self.pid = os.getpid()
 
     @property
     def enabled(self):
         settings = global_settings()
         if platform.python_implementation() == "PyPy" or not settings:
             return False
-        else:
+        # This might be inheriting from Settings instead of TopLevelSettings
+        elif settings and hasattr(settings, "gc_runtime_metrics"):
             return settings.gc_runtime_metrics.enabled
+        else:
+            return False
 
     @property
     def top_object_count_limit(self):