メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0250000 38.7000000, 141.0312500 38.7000000, 141.0312500 38.7041667, 141.0250000 38.7041667, 141.0250000 38.7000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral