メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4125000 43.8541667, 142.4187500 43.8541667, 142.4187500 43.8583333, 142.4125000 43.8583333, 142.4125000 43.8541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral