メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3875000 38.8333333, 141.3937500 38.8333333, 141.3937500 38.8375000, 141.3875000 38.8375000, 141.3875000 38.8333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral