Fixed a blunder in test_usm_ndarray_operations

This prevented it from exercising methods of the namespace

Author: oleksandr-pavlyk

dpctl/tests/test_usm_ndarray_operators.py

@@ -22,25 +22,25 @@
 
 class Dummy:
     @staticmethod
-    def __abs__(a):
+    def abs(a):
         return a
 
     @staticmethod
-    def __add__(a, b):
+    def add(a, b):
         if isinstance(a, dpt.usm_ndarray):
             return a
         else:
             return b
 
     @staticmethod
-    def __sub__(a, b):
+    def subtract(a, b):
         if isinstance(a, dpt.usm_ndarray):
             return a
         else:
             return b
 
     @staticmethod
-    def __mul__(a, b):
+    def multiply(a, b):
         if isinstance(a, dpt.usm_ndarray):
             return a
         else:
@@ -51,6 +51,7 @@ def __mul__(a, b):
 def test_fp_ops(namespace):
     X = dpt.usm_ndarray(1, "d")
     X._set_namespace(namespace)
+    assert X.__array_namespace__() is namespace
     X[0] = -2.5
     X.__abs__()
     X.__add__(1.0)
@@ -75,8 +76,10 @@ def test_fp_ops(namespace):
     X.__imul__(X)
     X.__itruediv__(1.0)
     X.__ifloordiv__(1.0)
+
     X = dpt.usm_ndarray(1, "i4")
     X._set_namespace(namespace)
+    assert X.__array_namespace__() is namespace
     X.__lshift__(2)
     X.__rshift__(2)
     X.__rlshift__(2)
@@ -99,8 +102,10 @@ def test_fp_ops(namespace):
     X.__pow__(2)
     X.__rpow__(2)
     X.__ipow__(2)
+
     M = dpt.from_numpy(np.eye(3, 3, dtype="d"))
     X._set_namespace(namespace)
+    assert X.__array_namespace__() is namespace
     M.__matmul__(M)
     M.__imatmul__(M)
     M.__rmatmul__(M)