'Render the contents of `oeb_book` (which is an instance of
:class:`calibre.ebooks.oeb.OEBBook`) to the file specified by output.
:param output: Either a file like object or a string. If it is a string
it is the path to a directory that may or may not exist. The output
plugin should write its output into that directory. If it is a file like
object, the output plugin should write its output into the file.
:param input_plugin: The input plugin that was used at the beginning of
the conversion pipeline.
:param opts: Conversion options. Guaranteed to have attributes
corresponding to the OptionRecommendations of this plugin.
:param log: The logger. Print debug/info messages etc. using this.'

def convert(self, oeb_book, output, input_plugin, opts, log):

    raise NotImplementedError
