メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.1562500 31.7875000, 131.1625000 31.7875000, 131.1625000 31.7916667, 131.1562500 31.7916667, 131.1562500 31.7875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral