メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8750000 42.6000000, 141.8812500 42.6000000, 141.8812500 42.6041667, 141.8750000 42.6041667, 141.8750000 42.6000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral