メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5250000 35.6958334, 138.5312500 35.6958334, 138.5312500 35.7000000, 138.5250000 35.7000000, 138.5250000 35.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral