code: def opacity(self):
          
          in_node = self.inputNode()
          out_node = self.outputNode()
  
          if ( in_node and out_node and \
                       (in_node.isIsolateHidden() or out_node.isIsolateHidden()) ):
              return 0.1
  
          opacity = super(XNodeConnection, self).opacity()
          layer = self.layer()
          if layer:
              return layer.opacity() * opacity
  
          return opacity
docs: Returns the opacity amount for this connection.
          
          :return     <float>