def fill_document(doc):
    """Add a section, a subsection and some text to the document.

    :param doc: the document
    :type doc: :class:`pylatex.document.Document` instance
    """
    with doc.create(Section('A section')):
        doc.append('Some regular text and some ')
        doc.append(italic('italic text. '))

        with doc.create(Subsection('A subsection')):
            doc.append('Also some crazy characters: $&#{}')
Add a section, a subsection and some text to the document.

    :param doc: the document
    :type doc: :class:`pylatex.document.Document` instance