Marshals the IE options to the correct object.

def to_capabilities(self):
        """Marshals the IE options to the correct object."""
        caps = self._caps

        opts = self._options.copy()
        if len(self._arguments) > 0:
            opts[self.SWITCHES] = ' '.join(self._arguments)

        if len(self._additional) > 0:
            opts.update(self._additional)

        if len(opts) > 0:
            caps[Options.KEY] = opts
        return caps