docstr: Single line test
docstr_tok: ["Single","line","test"]
code: def test_single_numeric_line(self):
      """Single line test"""
      single_line = self.data[self.data["category1"] == "a"]
      ch = chartify.Chart(second_y_axis=True)
      ch.second_axis.plot.line(
          single_line, x_column="number1", y_column="number2"
      )
      assert np.array_equal(ch.data[0]["number1"], [1.0, 2.0, 3.0])
      assert np.array_equal(ch.data[0]["number2"], [5, 10, 0])
  
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 4 for calling the TestSecondYChart obj's underlying member method code with example usage: obj.test_single_numeric_line() without return types