メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.9187500 36.9916667, 137.9250000 36.9916667, 137.9250000 36.9958334, 137.9187500 36.9958334, 137.9187500 36.9916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral