メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2000000 36.7125000, 138.2062500 36.7125000, 138.2062500 36.7166667, 138.2000000 36.7166667, 138.2000000 36.7125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral