メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.7375000 38.7125000, 139.7437500 38.7125000, 139.7437500 38.7166667, 139.7375000 38.7166667, 139.7375000 38.7125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral