add super call to add method

horizonmetrics.py

@@ -16,7 +16,7 @@
 import evaluate
 import datasets
 
-from seametrics.horizon.utils import xy_points_to_slope_midpoint, calculate_horizon_error, calculate_horizon_error_across_sequence
+from seametrics.horizon.utils import *
 
 # TODO: Add BibTeX citation
 _CITATION = """\
@@ -119,6 +119,11 @@ class horizonmetrics(evaluate.Metric):
             self.slope_error_list.append(slope_error)
             self.midpoint_error_list.append(midpoint_error)
 
+        # does not impact the metric, but is required for the interface x_x
+        super(evaluate.Metric, self).add(prediction=predictions,
+                                         references=references,
+                                         **kwargs)
+
     def _compute(self):
         """
         Compute the horizon error across the sequence.