def to_representation(self, value):
        request = self.context.get('request', None)
        format = self.context.get('format', None)

        assert request is not None, (
            "`%s` requires the request in the serializer"
            " context. Add `context={'request': request}` when instantiating "
            "the serializer." % self.__class__.__name__
        )

        # By default use whatever format is given for the current context
        # unless the target is a different type to the source.
        #
        # Eg. Consider a HyperlinkedIdentityField pointing from a json
        # representation to an html property of that representation...
        #
        # '/snippets/1/' should link to '/snippets/1/highlight/'
        # ...but...
        # '/snippets/1/.json' should link to '/snippets/1/highlight/.html'
        if format and self.format and self.format != format:
            format = self.format

        # Return the hyperlink, or error if incorrectly configured.
        try:
            url = self.get_url(value, self.view_name, request, format)
        except NoReverseMatch:
            msg = (
                'Could not resolve URL for hyperlinked relationship using '
                'view name "%s". You may have failed to include the related '
                'model in your API, or incorrectly configured the '
                '`lookup_field` attribute on this field.'
            )
            if value in ('', None):
                value_string = {'': 'the empty string', None: 'None'}[value]
                msg += (
                    " WARNING: The value of the field on the model instance "
                    "was %s, which may be why it didn't match any "
                    "entries in your URL conf." % value_string
                )
            raise ImproperlyConfigured(msg % self.view_name)

        if url is None:
            return None

        name = self.get_name(value)
        return Hyperlink(url, name)
dataset/ETHPy150Open tomchristie/django-rest-framework/rest_framework/relations.py/HyperlinkedRelatedField.to_representation/original