メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2937500 43.9291667, 142.3000000 43.9291667, 142.3000000 43.9333333, 142.2937500 43.9333333, 142.2937500 43.9291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral