code: def Dump(self, key = None):
          
          import pprint
          pp = pprint.PrettyPrinter(indent=2)
          if key:
              dict = self.Dictionary(key)
          else:
              dict = self.Dictionary()
          return pp.pformat(dict)
docs: Using the standard Python pretty printer, return the contents of the
          scons build environment as a string.
  
          If the key passed in is anything other than None, then that will
          be used as an index into the build environment dictionary and
          whatever is found there will be fed into the pretty printer. Note
          that this key is case sensitive.