メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.2000000 38.9833333, 141.2062500 38.9833333, 141.2062500 38.9875000, 141.2000000 38.9875000, 141.2000000 38.9833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral