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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 include_flags(self, arch):
        '''Returns a string with the include folders'''
        openssl_includes = join(self.get_build_dir(arch.arch), 'include')
        return (' -I' + openssl_includes +
                ' -I' + join(openssl_includes, 'internal') +
                ' -I' + join(openssl_includes, 'openssl'))