メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.2312500 31.4500000, 131.2375000 31.4500000, 131.2375000 31.4541667, 131.2312500 31.4541667, 131.2312500 31.4500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral