メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6625000 45.4250000, 141.6687500 45.4250000, 141.6687500 45.4291667, 141.6625000 45.4291667, 141.6625000 45.4250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral