メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7500000 43.2041667, 141.7562500 43.2041667, 141.7562500 43.2083333, 141.7500000 43.2083333, 141.7500000 43.2041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral