make version of ts_mon compatible with appengine

infra_libs/ts_mon/common/metrics.py

Index: infra_libs/ts_mon/common/metrics.py
diff --git a/infra_libs/ts_mon/metrics.py b/infra_libs/ts_mon/common/metrics.py
similarity index 96%
rename from infra_libs/ts_mon/metrics.py
rename to infra_libs/ts_mon/common/metrics.py
index fa986e6e115441c8eaaf97f57c1577658d5e0337..446ad5f112142f6e4cf6c034f66c4a220fe94445 100644
--- a/infra_libs/ts_mon/metrics.py
+++ b/infra_libs/ts_mon/common/metrics.py
@@ -9,11 +9,16 @@ import copy
 import threading
 import time
 
-from monacq.proto import metrics_pb2
-
-from infra_libs.ts_mon import distribution
-from infra_libs.ts_mon import errors
-from infra_libs.ts_mon import interface
+try:
+  from infra_libs.ts_mon import interface
+  from infra_libs.ts_mon.common import distribution
+  from infra_libs.ts_mon.common import errors
+  from monacq.proto import metrics_pb2
+except ImportError: # pragma: no cover
+  import interface
+  from common import distribution
+  from common import errors
+  from monacq.proto import metrics_pb2
 
 
 MICROSECONDS_PER_SECOND = 1000000
@@ -69,6 +74,14 @@ class Metric(object):
 
     interface.register(self)
 
+
+  def __eq__(self, other):
+    name = self._name == other._name
+    target = self._target == other._target
+    field = self._fields == other._fields
+    instance_type = type(self) == type(other)
+    return name and target and field and instance_type
+
   def unregister(self):
     interface.unregister(self)