メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((145.3375000 44.3208334, 145.3437500 44.3208334, 145.3437500 44.3250000, 145.3375000 44.3250000, 145.3375000 44.3208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral