Add methods for filtering on meters to corpus.py

            if all(fil(line) for fil in line_filters)

        )

    def get_lines_with_meter(self, meters):

        filters = [lambda tag: any((meter in tag.attrs['class'])

                                   for meter in meters)]

        if self.root.find(name='div', class_='poem'):

            yield from (

                line

                for poem in self.get_poems(filters)

                for line in poem.find_all(name='div', class_='line')

            )

        else:

            self.get_lines(filters)

class HypotacticCorpus:

        )

    def get_lines_with_meter(self, meters):

        filters = [lambda line: any((meter in line.attrs['class'])

                                    for meter in meters)]

        yield from self.get_lines(filters)

        yield from (

            line

            for doc in self.documents

            for line in doc.get_lines_with_meter(meters)

        )

    def save_lines(self, file_handle, lines, title='Saved Poems',

                   base_html=BASE_HTML):

                   base_html=BASE_HTML, pretty=False):

        soup = BeautifulSoup(base_html, self.parser)

        title_tag = soup.new_tag('title')

            latin.append(line)

        soup.find(name='body').append(latin)

        file_handle.write(soup.prettify())

        if pretty:

            output = soup.prettify()

        else:

            output = str(soup)

        file_handle.write(output)