メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0500000 31.6708334, 131.0562500 31.6708334, 131.0562500 31.6750000, 131.0500000 31.6750000, 131.0500000 31.6708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral