メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4000000 37.2541667, 138.4062500 37.2541667, 138.4062500 37.2583333, 138.4000000 37.2583333, 138.4000000 37.2541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral