メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((137.8937500 35.8458334, 137.9000000 35.8458334, 137.9000000 35.8500000, 137.8937500 35.8500000, 137.8937500 35.8458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral