メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.4375000 42.9375000, 143.4437500 42.9375000, 143.4437500 42.9416667, 143.4375000 42.9416667, 143.4375000 42.9375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral