メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8500000 44.7125000, 141.8562500 44.7125000, 141.8562500 44.7166667, 141.8500000 44.7166667, 141.8500000 44.7125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral