メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3687500 43.1000000, 141.3750000 43.1000000, 141.3750000 43.1041667, 141.3687500 43.1041667, 141.3687500 43.1000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral