code: def Split(self, arg):
          
  
          if SCons.Util.is_List(arg):
              return list(map(self.subst, arg))
          elif SCons.Util.is_String(arg):
              return self.subst(arg).split()
          else:
              return [self.subst(arg)]
docs: This function converts a string or list into a list of strings
          or Nodes.  This makes things easier for users by allowing files to
          be specified as a white-space separated list to be split.
  
          The input rules are:
              - A single string containing names separated by spaces. These will be
                split apart at the spaces.
              - A single Node instance
              - A list containing either strings or Node instances. Any strings
                in the list are not split at spaces.
  
          In all cases, the function returns a list of Nodes and strings.