メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3875000 43.7041667, 142.3937500 43.7041667, 142.3937500 43.7083333, 142.3875000 43.7083333, 142.3875000 43.7041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral