メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.6625000 44.0916667, 143.6687500 44.0916667, 143.6687500 44.0958334, 143.6625000 44.0958334, 143.6625000 44.0916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral