code: def _select_case(self, role, case):
          
          # select the case
          elem = Select(self._browser.find_element_by_id('select-dut'))
          elem.select_by_value(str(role))
          time.sleep(1)
  
          checkbox = None
          wait_until(lambda: self._browser.find_elements_by_css_selector('.tree-node .tree-title') and True)
          elems = self._browser.find_elements_by_css_selector('.tree-node .tree-title')
          finder = re.compile(r'.*\b' + case + r'\b')
          finder_dotted = re.compile(r'.*\b' + case.replace(' ', r'\.') + r'\b')
          for elem in elems:
              action_chains = ActionChains(self._browser)
              action_chains.move_to_element(elem)
              action_chains.perform()
              logger.debug(elem.text)
              if finder.match(elem.text) or finder_dotted.match(elem.text):
                  parent = elem.find_element_by_xpath('..')
                  checkbox = parent.find_element_by_class_name('tree-checkbox')
                  break
  
          if not checkbox:
              time.sleep(5)
              raise Exception('Failed to find the case')
  
          self._browser.execute_script("$('.overview').css('left', '0')")
          checkbox.click()
          time.sleep(1)
  
          elem = self._browser.find_element_by_id('runTest')
          elem.click()
          if not wait_until(lambda: self._browser.find_element_by_id('stopTest') and True, 10):
              raise Exception('Failed to start test case')
docs: Select the test case.