メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.3937500 34.6958334, 137.4000000 34.6958334, 137.4000000 34.7000000, 137.3937500 34.7000000, 137.3937500 34.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral