メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.9812500 42.1000000, 142.9875000 42.1000000, 142.9875000 42.1041667, 142.9812500 42.1041667, 142.9812500 42.1000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral