メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9625000 42.5500000, 141.9687500 42.5500000, 141.9687500 42.5541667, 141.9625000 42.5541667, 141.9625000 42.5500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral