docs: def return_val(self):
          """
          Returns the return value of the function, as a ParamDoc with an
          empty name:
  
          >>> comments = parse_comments_for_file('examples/module_closure.js')
          >>> fn1 = FunctionDoc(comments[1])
          >>> fn1.return_val.name
          ''
          >>> fn1.return_val.doc
          'Some value'
          >>> fn1.return_val.type
          'String'
  
          >>> fn2 = FunctionDoc(comments[2])
          >>> fn2.return_val.doc
          'Some property of the elements.'
          >>> fn2.return_val.type
          'Array<String>'
  
          """
          ret = self.get('return') or self.get('returns')
          type = self.get('type')
          if '{' in ret and '}' in ret:
              if not '}  ' in ret:
                  # Ensure that name is empty
                  ret = ret.replace('} ', '}  ')
              return ParamDoc(ret)
          if ret and type:
              return ParamDoc('{%s}  %s' % (type, ret))
          return ParamDoc(ret)