code: def merge(a, b):
      
      for item in a:
          setattr(b, item[0], item[1])
          b.__metadata__ = b.__metadata__
      return b
docs: Merge all attributes and metadata from I{a} to I{b}.
      @param a: A I{source} object
      @type a: L{Object}
      @param b: A I{destination} object
      @type b: L{Object}