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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 pretty_print(ast, indent_str=' '):
 """ Simple pretty print function; returns a string rendering of an input AST of an ES5 Program. arguments ast The AST to pretty print indent_str The string used for indentations. Defaults to two spaces. """


    return ''.join(chunk.text for chunk in pretty_printer(indent_str)(ast))