メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.4687500 36.8958334, 137.4750000 36.8958334, 137.4750000 36.9000000, 137.4687500 36.9000000, 137.4687500 36.8958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral