anchor.diff:  
   -define(DATAFRAME, 'pandas.core.frame.DataFrame').
   -define(SERIES, 'pandas.core.frame.Series').
  +-define(PYODBC, 'pyodbc.conn').
   
   -export([all/0, init_per_testcase/2, end_per_testcase/2]).
   -export([test_jun_pandas_read_csv/1,
  
positive.code:      test_jun_pandas_to_json,
       test_jun_pandas_to_erl,
       test_jun_pandas_bad_call,
       test_jun_pandas_to_datetime].
  
  init_per_testcase(_, _Config) ->
      % for each case start a new worker
  
negative.code:     {ok, {?SERIES, Series}} = jun_pandas:single_selection(Pid, DataFrame, 'age', []),
      {ok, SeriesDt} = jun_pandas:to_datetime(Pid, Series, []),
      ?assertMatch({?SERIES, _}, SeriesDt).
  
  test_jun_pandas_read_sql([{jun_worker, Pid} | _]) ->
      {error,{Error, _}} = jun_pandas:read_sql(Pid, ['SELECT * FROM jun.table'], [{dsn, 'DSN'},
          {username, 'jun'}, {password, 'jun'}, {database, 'jun-database'}]),
      ?assertEqual('pyodbc.InterfaceError', Error). 
  