メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.0875000 36.6000000, 137.0937500 36.6000000, 137.0937500 36.6041667, 137.0875000 36.6041667, 137.0875000 36.6000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral