メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.7937500 38.7958334, 139.8000000 38.7958334, 139.8000000 38.8000000, 139.7937500 38.8000000, 139.7937500 38.7958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral