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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 load(root_file, use_proxy=True, key=None):
 """Load an object from a ROOT TFile. `root_file` may be an open ROOT file or directory, or a string path to an existing ROOT file. """

    if isinstance(root_file, string_types):
        root_file = root_open(root_file)
        own_file = True
    else:
        own_file = False
    obj = Unpickler(root_file, use_proxy).load(key)
    if own_file:
        root_file.Close()
    return obj