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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def build():
 """ Builds pages given template.jinja, style.css, and content.rst produces index.html. """

    test_files()
    with open('content.rst') as f:
        content = publish_parts(f.read(), writer_name='html')
        title = content['title']
        body =  content['html_body'].replace('\n',' ')

    with open('template.jinja', 'r') as f:
        loader = FileSystemLoader(getcwd())
        env= Environment(loader=loader)
        template = env.get_template('template.jinja')
        page =  template.render(title=title,
                                content=body)

    with open('index.html', 'w') as f:
        f.write(page)