code: def test_currency_check(dataframe):
      """Test conversion raises exception for invalid currency."""
      with pytest.raises(ValueError):
          assert dataframe.convert_currency(
              "a", "USD", "INVALID-CURRENCY"
          )
  
file_path: pyjanitor/tests/finance/test_convert_currency.py
imports: from datetime import date, datetime
  import pytest
  import requests
  from janitor.finance import convert_currency
label_desc: Use image node_id 5 for calling a global function with example usage: test_currency_check(dataframe) without return types