メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5812500 44.9208334, 142.5875000 44.9208334, 142.5875000 44.9250000, 142.5812500 44.9250000, 142.5812500 44.9208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral