'Select columns returns COPY of data and all column
attributes'

def test_select_columns(self, table_data):

    self.t = table_data.Table(table_data.COLS)
    self.tc = self.t.columns
    for columns in (('a', 'c'), ['a', 'c']):
        t2 = self.t[columns]
        assert np.all((t2['a'] == table_data.DATA['a']))
        assert np.all((t2['c'] == table_data.DATA['c']))
        assert t2['a'].attrs_equal(table_data.COLS[0])
        assert t2['c'].attrs_equal(table_data.COLS[2])
        t2['a'][0] = 0
        assert np.all((self.t.as_array() == table_data.DATA))
        assert np.any((t2['a'] != table_data.DATA['a']))
        assert (t2.masked == self.t.masked)
        assert (t2._column_class == self.t._column_class)
