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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def dnld_goa(self, species, ext='gaf', item=None, fileout=None):
 """Download GOA source file name on EMBL-EBI ftp server."""

        basename = self.get_basename(species, ext, item)
        src = os.path.join(self.ftp_src_goa, species.upper(), "{F}.gz".format(F=basename))
        dst = os.path.join(os.getcwd(), basename) if fileout is None else fileout
        dnld_file(src, dst, prt=sys.stdout, loading_bar=None)
        return dst