code: def poplistitem(self, last=True):
          
          if not self._items:
              s = 'poplistitem(): %s is empty' % self.__class__.__name__
              raise KeyError(s)
  
          key = self.keys()[-1 if last else 0]
          return key, self.poplist(key)
docs: Pop and return a key:valuelist item comprised of a key and that key's
          list of values. If <last> is False, a key:valuelist item comprised of
          keys()[0] and its list of values is popped and returned. If <last> is
          True, a key:valuelist item comprised of keys()[-1] and its list of
          values is popped and returned.
  
          Example:
            omd = omdict([(1,1), (1,11), (1,111), (2,2), (3,3)])
            omd.poplistitem(last=True) == (3,[3])
            omd.poplistitem(last=False) == (1,[1,11,111])
  
          Params:
            last: Boolean whether to pop the first or last key and its associated
              list of values.
          Raises: KeyError if the dictionary is empty.
          Returns: A two-tuple comprised of the first or last key and its
            associated list of values.