メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7312500 42.8041667, 141.7375000 42.8041667, 141.7375000 42.8083333, 141.7312500 42.8083333, 141.7312500 42.8041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral