メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2500000 36.9500000, 138.2562500 36.9500000, 138.2562500 36.9541667, 138.2500000 36.9541667, 138.2500000 36.9500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral