code: def test_init(self):
      with pytest.raises(ValueError):
          chartify.Chart(y_axis_type="categorical", second_y_axis=True)
      ch = chartify.Chart(y_axis_type="linear", second_y_axis=True)
      assert ch._second_y_axis_type == "linear"
  
file_path: chartify/tests/test_chart.py
imports: import chartify
  import numpy
  import pandas
  import pytest
  from selenium.common.exceptions import WebDriverException
label_desc: Use image node_id 2 for calling the TestSecondYChart obj's underlying member method code with example usage: obj.test_init() without return types