corrected overlapping test names

Author: flexatone

test/test_util.py

@@ -339,15 +339,12 @@ def test_isna_element_d(self) -> None:
         self.assertTrue(isna_element(ts))
 
 
-    def test_isna_element_d(self) -> None:
+    def test_isna_element_e(self) -> None:
         from types import SimpleNamespace
         sn = SimpleNamespace()
         sn.to_numpy = None
         self.assertFalse(isna_element(sn))
 
-
-
-
     #---------------------------------------------------------------------------
 
     def test_dtype_from_element_core_dtypes(self) -> None: