Remove redundant method
Remove redundant method

jupyter/jupyter-js-filebrowser,jupyter/jupyter-js-filebrowser,jupyter/jupyter-js-filebrowser,jupyter/jupyter-js-filebrowser,blink1073/jupyter-js-filebrowser,blink1073/jupyter-js-filebrowser,blink1073/jupyter-js-filebrowser,blink1073/jupyter-js-filebrowser,jupyter/jupyter-js-filebrowser,blink1073/jupyter-js-filebrowser