メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4062500 44.0250000, 142.4125000 44.0250000, 142.4125000 44.0291667, 142.4062500 44.0291667, 142.4062500 44.0250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral