メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0750000 31.8541667, 131.0812500 31.8541667, 131.0812500 31.8583333, 131.0750000 31.8583333, 131.0750000 31.8541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral