メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.6625000 42.7958334, 143.6687500 42.7958334, 143.6687500 42.8000000, 143.6625000 42.8000000, 143.6625000 42.7958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral