メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6125000 45.1791667, 141.6187500 45.1791667, 141.6187500 45.1833333, 141.6125000 45.1833333, 141.6125000 45.1791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral