メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.8000000 44.6791667, 142.8062500 44.6791667, 142.8062500 44.6833333, 142.8000000 44.6833333, 142.8000000 44.6791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral