メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.1500000 42.8750000, 143.1562500 42.8750000, 143.1562500 42.8791667, 143.1500000 42.8791667, 143.1500000 42.8750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral