メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.9750000 42.8541667, 142.9812500 42.8541667, 142.9812500 42.8583333, 142.9750000 42.8583333, 142.9750000 42.8541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral