メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.5937500 43.6791667, 143.6000000 43.6791667, 143.6000000 43.6833333, 143.5937500 43.6833333, 143.5937500 43.6791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral