メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.2187500 42.8375000, 143.2250000 42.8375000, 143.2250000 42.8416667, 143.2187500 42.8416667, 143.2187500 42.8375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral