added unit test

Author: btel

pandas/tests/indexes/multi/test_indexing.py

@@ -346,3 +346,7 @@ def test_get_indexer_categorical_time():
          Categorical(date_range("2012-01-01", periods=3, freq='H'))])
     result = midx.get_indexer(midx)
     tm.assert_numpy_array_equal(result, np.arange(9, dtype=np.intp))
+
+def test_searchsorted():
+    i = MultiIndex.from_tuples([('a', 0), ('b', 1)]).searchsorted(('b', 0))
+    assert i == 1