メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7375000 42.6250000, 141.7437500 42.6250000, 141.7437500 42.6291667, 141.7375000 42.6291667, 141.7375000 42.6250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral