Get mapping for given resource or item schema.

        :param schema: resource or dict/list type item schema

def _get_mapping(self, schema):
        """Get mapping for given resource or item schema.

        :param schema: resource or dict/list type item schema
        """
        properties = {}
        for field, field_schema in schema.items():
            field_mapping = self._get_field_mapping(field_schema)
            if field_mapping:
                properties[field] = field_mapping
        return {'properties': properties}