メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.4375000 36.8875000, 137.4437500 36.8875000, 137.4437500 36.8916667, 137.4375000 36.8916667, 137.4375000 36.8875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral