'Return a list of all subsection titles on the page
for the section at index `section_index` (starts at 1).'

def _subsection_titles(self, section_index):

    subsection_css = '.course-navigation    .chapter-content-container:nth-of-type({0})    .menu-item    a    p:nth-of-type(1)'.format(section_index)
    return self.q(css=subsection_css).map((lambda el: (el.text.strip().split('\n')[0] if el.is_displayed() else el.get_attribute('innerHTML').strip()))).results
