メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0437500 31.6958334, 131.0500000 31.6958334, 131.0500000 31.7000000, 131.0437500 31.7000000, 131.0437500 31.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral