$quiz->set( $prop, $quiz_data[ $prop ] );
				}
			}

			if ( isset( $quiz_data['questions'] ) && is_array( $quiz_data['questions'] ) ) {
				$res['questions'] = self::update_questions( $quiz_data['questions'], $quiz );
			}

			// Update all custom fields.
			self::update_custom_schemas( 'quiz', $quiz, $quiz_data );

		}

		return $res;

	}

	/**
	 * Update a section with data from the heartbeat
	 *
	 * @since 3.16.0
	 * @since 3.16.11 Unknown.
	 *
	 * @param array       $section_data Array of section data.
	 * @param LLMS_Course $course_id    Instance of the parent LLMS_Course.
	 * @return array
	 */
	private static function update_section( $section_data, $course_id ) {

		$res = array_merge(
			$section_data,
			array(
				'orig_id' => $section_data['id'],
			)
		);

		// Create a new section.
		if ( self::is_temp_id( $section_data['id'] ) ) {

			$section = new LLMS_Section( 'new' );
			$section->set( 'parent_course', $course_id );

			// Update existing section.
		} else {

			$section = llms_get_post( $section_data['id'] );

		}

		// We don't have a proper section to work with...
		if ( empty( $section ) || ! is_a( $section, 'LLMS_Section' ) ) {
			// Translators: %s = Section post id.