メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.2437500 42.9000000, 143.2500000 42.9000000, 143.2500000 42.9041667, 143.2437500 42.9041667, 143.2437500 42.9000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral