メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4562500 44.1708334, 142.4625000 44.1708334, 142.4625000 44.1750000, 142.4562500 44.1750000, 142.4562500 44.1708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral