'Return a two tuple of (cls, kwargs) to build a serializer field with.'

def build_field(self, field_name, info, model_class, nested_depth):

    if (field_name in info.fields_and_pk):
        model_field = info.fields_and_pk[field_name]
        return self.build_standard_field(field_name, model_field)
    elif (field_name in info.relations):
        relation_info = info.relations[field_name]
        if (not nested_depth):
            return self.build_relational_field(field_name, relation_info)
        else:
            return self.build_nested_field(field_name, relation_info, nested_depth)
    elif hasattr(model_class, field_name):
        return self.build_property_field(field_name, model_class)
    elif (field_name == self.url_field_name):
        return self.build_url_field(field_name, model_class)
    return self.build_unknown_field(field_name, model_class)
