DataGrid dataGrid = new TransientDataGrid();
String result = dataGrid.write("key", "value");
assertEquals(result, "value");
result = dataGrid.read("key");
assertEquals(result, "value");
result = dataGrid.take("key");
assertEquals(result, "value");
result = dataGrid.read("key");
assertNull(result);
result = dataGrid.read("newKey");
assertNull(result);