メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3187500 36.7916667, 138.3250000 36.7916667, 138.3250000 36.7958334, 138.3187500 36.7958334, 138.3187500 36.7916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral