メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.8375000 38.6000000, 139.8437500 38.6000000, 139.8437500 38.6041667, 139.8375000 38.6041667, 139.8375000 38.6000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral