code: def AppendENVPath(self, name, newpath, envname = 'ENV',
                        sep = os.pathsep, delete_existing=1):
          
  
          orig = ''
          if envname in self._dict and name in self._dict[envname]:
              orig = self._dict[envname][name]
  
          nv = SCons.Util.AppendPath(orig, newpath, sep, delete_existing,
                                     canonicalize=self._canonicalize)
  
          if envname not in self._dict:
              self._dict[envname] = {}
  
          self._dict[envname][name] = nv
docs: Append path elements to the path 'name' in the 'ENV'
          dictionary for this environment.  Will only add any particular
          path once, and will normpath and normcase all paths to help
          assure this.  This can also handle the case where the env
          variable is a list instead of a string.
  
          If delete_existing is 0, a newpath which is already in the path
          will not be moved to the end (it will be left where it is).