メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((136.9937500 36.9458334, 137.0000000 36.9458334, 137.0000000 36.9500000, 136.9937500 36.9500000, 136.9937500 36.9458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral