code: def test_string(self):
      url = _generate_url("arch", True)
      assert (
          url == self.stable + "search.html?q="
          "arch&check_keywords=yes&area=default"
      )
      url = _generate_url("arch", False)
      assert (
          url == self.devel + "search.html?q="
          "arch&check_keywords=yes&area=default"
      )
      url = _generate_url("dickey fuller", False)
      assert url == (
          self.devel + "search.html?q="
          "dickey+fuller&check_keywords=yes&area=default"
      )
  
file_path: statsmodels/statsmodels/tools/tests/test_web.py
imports: import pytest
  from numpy import array
  from statsmodels.regression.linear_model import OLS
  from statsmodels.tools.web import _generate_url, webdoc
label_desc: Use image node_id 1 for calling the TestWeb obj's underlying member method code with example usage: obj.test_string() without return types