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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 get_default_ENV(env):
 """ A fiddlin' little function that has an 'import SCons.Environment' which can't be moved to the top level without creating an import loop. Since this import creates a local variable named 'SCons', it blocks access to the global variable, so we move it here to prevent complaints about local variables being used uninitialized. """

    global default_ENV
    try:
        return env['ENV']
    except KeyError:
        if not default_ENV:
            import SCons.Environment
            # This is a hideously expensive way to get a default shell
            # environment.  What it really should do is run the platform
            # setup to get the default ENV.  Fortunately, it's incredibly
            # rare for an Environment not to have a shell environment, so
            # we're not going to worry about it overmuch.
            default_ENV = SCons.Environment.Environment()['ENV']
        return default_ENV