メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.6687500 44.1291667, 142.6750000 44.1291667, 142.6750000 44.1333333, 142.6687500 44.1333333, 142.6687500 44.1291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral