メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.6625000 44.8041667, 142.6687500 44.8041667, 142.6687500 44.8083333, 142.6625000 44.8083333, 142.6625000 44.8041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral