Add unit tests for tm.shares_memory (#55372)

Author: Aniketsy

pandas/tests/util/test_shares_memory.py

@@ -44,15 +44,15 @@ def test_shares_memory_numpy():
 def test_shares_memory_series():
     arr = np.arange(10)
     s = pd.Series(arr)
-    assert tm.shares_memory(arr, s)
+    assert tm.shares_memory(s, arr)
     s2 = pd.Series(np.arange(10))
     assert not tm.shares_memory(s, s2)
 
 
 def test_shares_memory_dataframe_single_block():
     arr = np.arange(10)
     df = pd.DataFrame({"a": arr})
-    assert tm.shares_memory(arr, df)
+    assert tm.shares_memory(df, arr)
     df2 = pd.DataFrame({"a": np.arange(10)})
     assert not tm.shares_memory(df, df2)
 
@@ -65,7 +65,5 @@ def test_shares_memory_rangeindex():
 
 def test_shares_memory_multiindex():
     idx = pd.MultiIndex.from_arrays([np.arange(10), np.arange(10, 20)])
-    arr = idx.codes[0]
-    assert tm.shares_memory(idx, arr)
     arr2 = np.arange(10)
     assert not tm.shares_memory(idx, arr2)