メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0625000 31.8416667, 131.0687500 31.8416667, 131.0687500 31.8458334, 131.0625000 31.8458334, 131.0625000 31.8416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral