メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8687500 42.6791667, 141.8750000 42.6791667, 141.8750000 42.6833333, 141.8687500 42.6833333, 141.8687500 42.6791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral