メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.7875000 42.8083333, 143.7937500 42.8083333, 143.7937500 42.8125000, 143.7875000 42.8125000, 143.7875000 42.8083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral