メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8875000 43.5875000, 141.8937500 43.5875000, 141.8937500 43.5916667, 141.8875000 43.5916667, 141.8875000 43.5875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral