メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.1500000 38.9458334, 141.1562500 38.9458334, 141.1562500 38.9500000, 141.1500000 38.9500000, 141.1500000 38.9458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral