メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.7625000 37.4833333, 138.7687500 37.4833333, 138.7687500 37.4875000, 138.7625000 37.4875000, 138.7625000 37.4833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral