メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0875000 38.4875000, 141.0937500 38.4875000, 141.0937500 38.4916667, 141.0875000 38.4916667, 141.0875000 38.4875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral