Fix test

Author: dcherian

xarray/plot/dataset_plot.py

@@ -386,7 +386,11 @@ def newplotfunc(
                 coordinates="figure",
             )
 
-        ax.set_title(ds[u]._title_for_slice())
+        if plotfunc.__name__ == "quiver":
+            title = ds[u]._title_for_slice()
+        else:
+            title = ds[x]._title_for_slice()
+        ax.set_title(title)
 
         return primitive