メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.0250000 36.5791667, 137.0312500 36.5791667, 137.0312500 36.5833333, 137.0250000 36.5833333, 137.0250000 36.5791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral