<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _open_ftp(self):
 # type: () -> FTP """Open an ftp object for the file."""

        ftp = self.fs._open_ftp()
        ftp.voidcmd(str("TYPE I"))
        return ftp