メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4250000 31.9166667, 131.4312500 31.9166667, 131.4312500 31.9208334, 131.4250000 31.9208334, 131.4250000 31.9166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral