メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.706387796971 44.3715128369842, 141.705853094143 44.3718577766439, 141.704780681656 44.3710155859768, 141.705291577421 44.3706797842068, 141.705355727821 44.3706383227615, 141.706427342756 44.3714873967015, 141.706387796971 44.3715128369842)) ^^http://www.opengis.net/ont/geosparql#wktLiteral