code: def is_opened(components):
          
          if components == None:
              return True
  
          result = True
          for component in components:
              result = result and Opener.is_opened_one(component)
  
          return result
docs: Checks if all components are opened.
  
          To be checked components must implement [[IOpenable]] interface.
          If they don't the call to this method returns true.
  
          :param components: a list of components that are to be checked.
  
          :return: true if all components are opened and false if at least one component is closed.