メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.7000000 42.7291667, 143.7062500 42.7291667, 143.7062500 42.7333333, 143.7000000 42.7333333, 143.7000000 42.7291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral