メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.404818962908 44.1671871225362, 142.404242606123 44.1671934193739, 142.404229184877 44.1661943316131, 142.406124433692 44.166205955443, 142.405920910111 44.1671367432182, 142.404818962908 44.1671871225362)) ^^http://www.opengis.net/ont/geosparql#wktLiteral