メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.0750000 42.5875000, 142.0812500 42.5875000, 142.0812500 42.5916667, 142.0750000 42.5916667, 142.0750000 42.5875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral