メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7250000 39.2875000, 141.7312500 39.2875000, 141.7312500 39.2916667, 141.7250000 39.2916667, 141.7250000 39.2875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral