メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6250000 35.4791667, 138.6312500 35.4791667, 138.6312500 35.4833333, 138.6250000 35.4833333, 138.6250000 35.4791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral