メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3937500 38.3916667, 141.4000000 38.3916667, 141.4000000 38.3958334, 141.3937500 38.3958334, 141.3937500 38.3916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral