メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.6500000 44.0500000, 142.6562500 44.0500000, 142.6562500 44.0541667, 142.6500000 44.0541667, 142.6500000 44.0500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral