メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3875000 37.1708334, 138.3937500 37.1708334, 138.3937500 37.1750000, 138.3875000 37.1750000, 138.3875000 37.1708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral