Extract peer assignment text (instructions).

        @param element_id: Element id to extract peer assignment instructions from.
        @type element_id: str

        @return: List of peer assignment text (instructions).
        @rtype: [str]

def _extract_peer_assignment_text(self, element_id):
        """
        Extract peer assignment text (instructions).

        @param element_id: Element id to extract peer assignment instructions from.
        @type element_id: str

        @return: List of peer assignment text (instructions).
        @rtype: [str]
        """
        dom = get_page(self._session, OPENCOURSE_PEER_ASSIGNMENT_INSTRUCTIONS,
                       json=True,
                       user_id=self._user_id,
                       course_id=self._course_id,
                       element_id=element_id)

        result = []

        for element in dom['elements']:
            # There is only one section with Instructions
            if 'introduction' in element['instructions']:
                result.append(element['instructions']
                              ['introduction']['definition']['value'])

            # But there may be multiple sections in Sections
            for section in element['instructions'].get('sections', []):
                section_value = section['content']['definition']['value']
                section_title = section.get('title')
                if section_title is not None:
                    # If section title is present, put it in the beginning of
                    # section value as if it was there.
                    section_value = ('<heading level="3">%s</heading>' %
                                     section_title) + section_value
                result.append(section_value)

        return result