メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5562500 42.8791667, 141.5625000 42.8791667, 141.5625000 42.8833333, 141.5562500 42.8833333, 141.5562500 42.8791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral