メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4875000 43.7000000, 142.4937500 43.7000000, 142.4937500 43.7041667, 142.4875000 43.7041667, 142.4875000 43.7000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral