メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6187500 37.2166667, 138.6250000 37.2166667, 138.6250000 37.2208334, 138.6187500 37.2208334, 138.6187500 37.2166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral