メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((144.2875000 43.9875000, 144.2937500 43.9875000, 144.2937500 43.9916667, 144.2875000 43.9916667, 144.2875000 43.9875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral