メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.6000000 38.6333333, 139.6062500 38.6333333, 139.6062500 38.6375000, 139.6000000 38.6375000, 139.6000000 38.6333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral