def perform_preflight_check(self):
failures = []<EOL>if not os.access(self.mount_path_base, os.W_OK):<EOL><INDENT>msg = ("<STR_LIT>"<EOL>"<STR_LIT>")<EOL>failures.append(msg.format(<EOL>path = self.mount_path_base<EOL>))<EOL><DEDENT>if which('<STR_LIT>') is None:<EOL><INDENT>msg = ("<STR_LIT>"<EOL>"<STR_LIT>")<EOL>failures.append(msg)<EOL><DEDENT>return len(failures) == <NUM_LIT:0>, failures<EOL>
Performs checks to see if we have everything needed to mount
        sshfs filesystems.
        :return: two-tuple (boolean checks_pass, list failure messages)