メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3625000 45.1291667, 142.3687500 45.1291667, 142.3687500 45.1333333, 142.3625000 45.1333333, 142.3625000 45.1291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral