メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8125000 42.9416667, 141.8187500 42.9416667, 141.8187500 42.9458334, 141.8125000 42.9458334, 141.8125000 42.9416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral