メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.8687500 36.9958334, 137.8750000 36.9958334, 137.8750000 37.0000000, 137.8687500 37.0000000, 137.8687500 36.9958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral