メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.4687500 36.8583333, 137.4750000 36.8583333, 137.4750000 36.8625000, 137.4687500 36.8625000, 137.4687500 36.8583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral