メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.8187500 38.8583333, 139.8250000 38.8583333, 139.8250000 38.8625000, 139.8187500 38.8625000, 139.8187500 38.8583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral