メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5812500 44.9083333, 142.5875000 44.9083333, 142.5875000 44.9125000, 142.5812500 44.9125000, 142.5812500 44.9083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral