メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8062500 39.8208334, 141.8125000 39.8208334, 141.8125000 39.8250000, 141.8062500 39.8250000, 141.8062500 39.8208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral