メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.7500000 42.2208334, 142.7562500 42.2208334, 142.7562500 42.2250000, 142.7500000 42.2250000, 142.7500000 42.2208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral