メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3937500 43.4250000, 142.4000000 43.4250000, 142.4000000 43.4291667, 142.3937500 43.4291667, 142.3937500 43.4250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral