How to use the pymapd._parsers.ColumnDetails function in pymapd

def test_upload_pandas_categorical(self, con):

        con.execute("DROP TABLE IF EXISTS test_categorical;")

        df = pd.DataFrame({"A": ["a", "b", "c", "a"]})
        df["B"] = df["A"].astype('category')

        # test that table created correctly when it doesn't exist on server
        con.load_table("test_categorical", df)
        ans = con.execute("select * from test_categorical").fetchall()

        assert ans == [('a', 'a'), ('b', 'b'), ('c', 'c'), ('a', 'a')]

        assert con.get_table_details("test_categorical") == \
            [ColumnDetails(name='A', type='STR', nullable=True, precision=0,
                           scale=0, comp_param=32, encoding='DICT',
                           is_array=False),
             ColumnDetails(name='B', type='STR', nullable=True, precision=0,
                           scale=0, comp_param=32, encoding='DICT',
                           is_array=False)]

        # load row-wise
        con.load_table("test_categorical", df, method="rows")

        # load columnar
        con.load_table("test_categorical", df, method="columnar")

        # load arrow
        con.load_table("test_categorical", df, method="arrow")

        # test end result

scale=0, comp_param=0),
                        is_reserved_keyword=False, src_name='')]
        result = _extract_column_details(data)

        expected = [
            ColumnDetails(name='date_', type='STR', nullable=True, precision=0,
                          scale=0, comp_param=32, encoding='DICT',
                          is_array=False),
            ColumnDetails(name='trans', type='STR', nullable=True, precision=0,
                          scale=0, comp_param=32, encoding='DICT',
                          is_array=False),
            ColumnDetails(name='symbol', type='STR', nullable=True,
                          precision=0, scale=0, comp_param=32,
                          encoding='DICT',
                          is_array=False),
            ColumnDetails(name='qty', type='INT', nullable=True, precision=0,
                          scale=0, comp_param=0, encoding='NONE',
                          is_array=False),
            ColumnDetails(name='price', type='FLOAT', nullable=True,
                          precision=0, scale=0, comp_param=0, encoding='NONE',
                          is_array=False),
            ColumnDetails(name='vol', type='FLOAT', nullable=True, precision=0,
                          scale=0, comp_param=0, encoding='NONE',
                          is_array=False)
        ]
        assert result == expected

ColumnDetails(name='trans', type='STR', nullable=True, precision=0,
                          scale=0, comp_param=32, encoding='DICT',
                          is_array=False),
            ColumnDetails(name='symbol', type='STR', nullable=True,
                          precision=0, scale=0, comp_param=32,
                          encoding='DICT', is_array=False),
            ColumnDetails(name='qty', type='INT', nullable=True, precision=0,
                          scale=0, comp_param=0, encoding='NONE',
                          is_array=False),
            ColumnDetails(name='price', type='FLOAT', nullable=True,
                          precision=0, scale=0, comp_param=0, encoding='NONE',
                          is_array=False),
            ColumnDetails(name='vol', type='FLOAT', nullable=True, precision=0,
                          scale=0, comp_param=0, encoding='NONE',
                          is_array=False),
            ColumnDetails(name='exchanges', type='STR', nullable=True,
                          precision=0, scale=0, comp_param=32, encoding='DICT',
                          is_array=True)
        ]
        assert result == expected
        c.execute('drop table if exists stocks;')