refining CountriesMergerTest

src/CountriesMerger.py

@@ -8,6 +8,9 @@ class CountriesMerger:
         def merge(series):
             series = series.dropna()
             return sorted(set().union(*series))
-        return (pd
-                .merge(dst, src, how='left', left_index=True, right_index=True)
-                .apply(merge, axis='columns'))
+        
+        mergedSeries = (pd
+                        .merge(dst, src, how='left', left_index=True, right_index=True)
+                        .apply(merge, axis='columns'))
+        mergedSeries.name = dst.name
+        return mergedSeries

src/CountriesMergerTest.py

@@ -21,4 +21,5 @@ class CountriesMergerTest(unittest.TestCase):
                 {
                     'NO72A': ['CountryA-1', 'CountryB-1'],
                     'EW096': ['CountryA-2']
-                }))
+                },
+                name=dstCountries.name))