メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8125000 37.5500000, 138.8187500 37.5500000, 138.8187500 37.5541667, 138.8125000 37.5541667, 138.8125000 37.5500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral