メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6562500 43.1583333, 141.6625000 43.1583333, 141.6625000 43.1625000, 141.6562500 43.1625000, 141.6562500 43.1583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral