メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4250000 36.9291667, 138.4312500 36.9291667, 138.4312500 36.9333333, 138.4250000 36.9333333, 138.4250000 36.9291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral