メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0062500 38.6958334, 141.0125000 38.6958334, 141.0125000 38.7000000, 141.0062500 38.7000000, 141.0062500 38.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral