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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 sconsign_dir(node):
 """Return the .sconsign file info for this directory, creating it first if necessary."""

    if not node._sconsign:
        import SCons.SConsign
        node._sconsign = SCons.SConsign.ForDirectory(node)
    return node._sconsign