メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.9375000 42.8416667, 142.9437500 42.8416667, 142.9437500 42.8458334, 142.9375000 42.8458334, 142.9375000 42.8416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral