def pretty_print(ast, indent_str='<STR_LIT:U+0020>'):
return '<STR_LIT>'.join(chunk.text for chunk in pretty_printer(indent_str)(ast))<EOL>
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.