メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4187500 44.3125000, 142.4250000 44.3125000, 142.4250000 44.3166667, 142.4187500 44.3166667, 142.4187500 44.3125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral