メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8250000 37.7250000, 138.8312500 37.7250000, 138.8312500 37.7291667, 138.8250000 37.7291667, 138.8250000 37.7250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral