メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.6937500 43.8500000, 142.7000000 43.8500000, 142.7000000 43.8541667, 142.6937500 43.8541667, 142.6937500 43.8500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral