メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6812500 42.7541667, 141.6875000 42.7541667, 141.6875000 42.7583333, 141.6812500 42.7583333, 141.6812500 42.7541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral