メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0625000 31.7291667, 131.0687500 31.7291667, 131.0687500 31.7333333, 131.0625000 31.7333333, 131.0625000 31.7291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral