code: def to_source(node, indentation=' ' * 4):
    
    if isinstance(node, gast.AST):
      node = gast.gast_to_ast(node)
    generator = SourceWithCommentGenerator(indentation, False,
                                           astor.string_repr.pretty_string)
    generator.visit(node)
    generator.result.append('\n')
    return astor.source_repr.pretty_source(generator.result).lstrip()
docs: Return source code of a given AST.