Check if the dest_file already exists on the file system (return boolean).

def check_file_exists(self, remote_cmd="dir home"):
        """Check if the dest_file already exists on the file system (return boolean)."""
        if self.direction == "put":
            remote_out = self.ssh_ctl_chan.send_command_expect(remote_cmd)
            search_string = r"Directory contents .*{}".format(self.dest_file)
            return bool(re.search(search_string, remote_out, flags=re.DOTALL))
        elif self.direction == "get":
            return os.path.exists(self.dest_file)