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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 ensure_symlink (src, dst):
 """Ensure the existence of a symbolic link pointing to src named dst. Returns a boolean indicating whether the symlink already existed. """

    try:
        os.symlink (src, dst)
    except OSError as e:
        if e.errno == 17: # EEXIST
            return True
        raise
    return False