code: def DOM_querySelector(self, nodeId, selector):
  		
  		assert isinstance(selector, (str,)
  		    ), "Argument 'selector' must be of type '['str']'. Received type: '%s'" % type(
  		    selector)
  		subdom_funcs = self.synchronous_command('DOM.querySelector', nodeId=
  		    nodeId, selector=selector)
  		return subdom_funcs
docs: Function path: DOM.querySelector
  			Domain: DOM
  			Method name: querySelector
  		
  			Parameters:
  				Required arguments:
  					'nodeId' (type: NodeId) -> Id of the node to query upon.
  					'selector' (type: string) -> Selector string.
  			Returns:
  				'nodeId' (type: NodeId) -> Query selector result.
  		
  			Description: Executes <code>querySelector</code> on a given node.