code: def test_select_returns_only_selected_columns(self):
      api_handler = Mock(CoinBaseHandler)
      api_handler.call_coinbase_api.return_value = pd.DataFrame(
          [
              [
                  "BTC-USD",  # symbol
                  34330.01,  # low
                  34623.21,  # high
                  34493.51,  # open
                  34349.16,  # close
                  719.064133,  # volume
                  1698710400,  # timestamp
                  "2023-10-30T20:00:00-04:00",  # timestamp_iso
              ]
          ]
      )
      trades_table = CoinBaseAggregatedTradesTable(api_handler)
  
      open_time_identifier = Identifier(path_str="open")
      close_time_identifier = Identifier(path_str="close")
      select_times = ast.Select(
          targets=[open_time_identifier, close_time_identifier],
          from_table="coinbase_candle_data",
          where='coinbase_candle_data.symbol = "BTC-USD"',
      )
  
      all_trade_data = trades_table.select(select_times)
      first_trade_data = all_trade_data.iloc[0]
  
      self.assertEqual(all_trade_data.shape[1], 2)
      self.assertEqual(first_trade_data["open"], 34493.51)
      self.assertEqual(first_trade_data["close"], 34349.16)
  
file_path: mindsdb/tests/handler_tests/test_coinbase_handler.py
imports: from mindsdb.integrations.handlers.coinbase_handler.coinbase_tables import CoinBaseAggregatedTradesTable
  from mindsdb.integrations.handlers.coinbase_handler.coinbase_handler import CoinBaseHandler
  from mindsdb_sql.parser import ast
  from mindsdb_sql.parser.ast.select.star import Star
  from mindsdb_sql.parser.ast.select.identifier import Identifier
  from unittest.mock import Mock
  import pandas
  import unittest
label_desc: Use image node_id 3 for calling the CoinBaseAggregatedTradesTableTest obj's underlying member method code with example usage: obj.test_select_returns_only_selected_columns() without return types