メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.2187500 38.4458334, 139.2250000 38.4458334, 139.2250000 38.4500000, 139.2187500 38.4500000, 139.2187500 38.4458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral