メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.5437500 32.1958334, 131.5500000 32.1958334, 131.5500000 32.2000000, 131.5437500 32.2000000, 131.5437500 32.1958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral