def _default_checker(x, y):
 if (x[0] != y[0]):
  raise Exception('Output mismatch.', {'performlinker': x[0], 'clinker': y[0]})

def _default_checker ( x , y ) : if ( x [ 0 ] != y [ 0 ] ) : raise Exception ( 'Output mismatch.' , { 'performlinker' : x [ 0 ] , 'clinker' : y [ 0 ] } )
default checker for duallinker .