GeglDistanceMetric =>
 { contig => 1,
   header => '',
   external => 1,
   symbols => [ qw(GEGL_DISTANCE_METRIC_EUCLIDEAN
     GEGL_DISTANCE_METRIC_MANHATTAN
     GEGL_DISTANCE_METRIC_CHEBYSHEV) ],
   mapping => { GEGL_DISTANCE_METRIC_EUCLIDEAN => '0',
         GEGL_DISTANCE_METRIC_MANHATTAN => '1',
         GEGL_DISTANCE_METRIC_CHEBYSHEV => '2' }
 },