メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4125000 37.9875000, 138.4187500 37.9875000, 138.4187500 37.9916667, 138.4125000 37.9916667, 138.4125000 37.9875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral