メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.4437500 35.6958334, 139.4500000 35.6958334, 139.4500000 35.7000000, 139.4437500 35.7000000, 139.4437500 35.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral