メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4250000 43.7500000, 142.4312500 43.7500000, 142.4312500 43.7541667, 142.4250000 43.7541667, 142.4250000 43.7500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral