メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.9125000 44.5916667, 142.9187500 44.5916667, 142.9187500 44.5958334, 142.9125000 44.5958334, 142.9125000 44.5916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral