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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 _serve_file(self, abspath, params):
 """Show a file. The actual content of the file is rendered by _handle_content. """

    relpath = os.path.relpath(abspath, self._root)
    breadcrumbs = self._create_breadcrumbs(relpath)
    link_path = urlunparse(['', '', relpath, '', urlencode(params), ''])
    args = self._default_template_args('file.html')
    args.update({'root_parent': os.path.dirname(self._root),
                 'breadcrumbs': breadcrumbs,
                 'link_path': link_path})
    content = self._renderer.render_name('base.html', args).encode("utf-8")
    self._send_content(content, 'text/html')