Return a `coreapi.Link` instance for the given endpoint.

def get_link(self, path, method, callback, view):
        """
        Return a `coreapi.Link` instance for the given endpoint.
        """
        fields = self.get_path_fields(path, method, callback, view)
        fields += self.get_serializer_fields(path, method, callback, view)
        fields += self.get_pagination_fields(path, method, callback, view)
        fields += self.get_filter_fields(path, method, callback, view)

        if fields and any([field.location in ('form', 'body')
                           for field in fields]):
            encoding = self.get_encoding(path, method, callback, view)
        else:
            encoding = None

        description = self.get_description(path, method, callback, view)

        link = coreapi.Link(
            url=urlparse.urljoin(self.url, path),
            action=method.lower(),
            encoding=encoding,
            description=description,
            fields=fields,
            transform=None,  # Not handled, but here for future reference
        )
        link._responses = self.get_responses(path, method, callback, view)
        link._produces = self.get_produces(path, method, callback, view)

        return link