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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 build(self):
 """Build packages from queue """

        packages = self.packages()
        if packages:
            for pkg in packages:
                if not os.path.exists(self.meta.build_path):
                    os.mkdir(self.meta.build_path)
                if not os.path.exists(self._SOURCES):
                    os.mkdir(self._SOURCES)
                sbo_url = sbo_search_pkg(pkg)
                sbo_dwn = SBoLink(sbo_url).tar_gz()
                source_dwn = SBoGrep(pkg).source().split()
                sources = []
                os.chdir(self.meta.build_path)
                script = sbo_dwn.split("/")[-1]
                Download(self.meta.build_path, sbo_dwn.split(),
                         repo="sbo").start()
                for src in source_dwn:
                    Download(self._SOURCES, src.split(), repo="sbo").start()
                    sources.append(src.split("/")[-1])
                BuildPackage(script, sources, self.meta.build_path,
                             auto=False).build()
        else:
            print("\nPackages not found in the queue for building\n")
            raise SystemExit(1)