メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.7937500 38.7875000, 139.8000000 38.7875000, 139.8000000 38.7916667, 139.7937500 38.7916667, 139.7937500 38.7875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral