メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8812500 42.7750000, 141.8875000 42.7750000, 141.8875000 42.7791667, 141.8812500 42.7791667, 141.8812500 42.7750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral