Adds tools to the plot.

        Args:
            *tools (Tool) : the tools to add to the Plot

        Returns:
            None

def add_tools(self, *tools):
        ''' Adds tools to the plot.

        Args:
            *tools (Tool) : the tools to add to the Plot

        Returns:
            None

        '''
        for tool in tools:
            if not isinstance(tool, Tool):
                raise ValueError("All arguments to add_tool must be Tool subclasses.")

            self.toolbar.tools.append(tool)