メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3625000 43.0875000, 141.3687500 43.0875000, 141.3687500 43.0916667, 141.3625000 43.0916667, 141.3625000 43.0875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral