メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8687500 37.6958334, 138.8750000 37.6958334, 138.8750000 37.7000000, 138.8687500 37.7000000, 138.8687500 37.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral