メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4000000 43.7375000, 142.4062500 43.7375000, 142.4062500 43.7416667, 142.4000000 43.7416667, 142.4000000 43.7375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral