メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.6937500 43.6041667, 143.7000000 43.6041667, 143.7000000 43.6083333, 143.6937500 43.6083333, 143.6937500 43.6041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral