test: [mocks] add convenience classmethod and __eq__

Facilitates unit tests of TTA

test/mocks.py

@@ -7,9 +7,16 @@ class MockInterval():
         self.end = end
         self.duration = end - start
 
+    @classmethod
+    def from_duration(cls, duration):
+        return cls(start=0, end=duration)
+
     def to_json(self):
         return {"start": self.start, "end": self.end}
 
+    def __eq__(self, other):
+        return self.start == other.start and self.end == other.end
+
 class MockFeature():
     """Mock feature object for testing"""
     def __init__(self, interval, source=None, feature_extractor="mock", score=0.0):
@@ -21,6 +28,10 @@ class MockFeature():
     def to_json(self):
         return {"interval": self.interval}
 
+    def __eq__(self, other):
+        return (self.interval == other.interval and self.source == other.source
+                and self.feature_extractor == other.feature_extractor)
+
 class MockSource():
     """Mock Source object for testing Feature"""
     def __init__(self, source=None, path=None):