Issue #761 better diff for apex reference check (added ascii art diff)

Author: dsamaey

openeo/testing/results.py

@@ -12,6 +12,7 @@
 import xarray
 import xarray.testing
 from scipy.spatial import ConvexHull
+from xarray import DataArray
 
 from openeo.rest.job import DEFAULT_JOB_RESULTS_FILENAME, BatchJob, JobResults
 from openeo.util import repr_truncate