メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3437500 36.8541667, 138.3500000 36.8541667, 138.3500000 36.8583333, 138.3437500 36.8583333, 138.3437500 36.8541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral