メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0437500 31.6791667, 131.0500000 31.6791667, 131.0500000 31.6833333, 131.0437500 31.6833333, 131.0437500 31.6791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral