メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0312500 31.4208334, 131.0375000 31.4208334, 131.0375000 31.4250000, 131.0312500 31.4250000, 131.0312500 31.4208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral