'convert AST to source code'

def gen_source(self, ast, customize, isLambda=0, returnNone=False):

    rn = self.return_none
    self.return_none = returnNone
    if (len(ast) == 0):
        self.print_(self.indent, 'pass')
    else:
        self.customize(customize)
        if isLambda:
            self.write(self.traverse(ast, isLambda=isLambda))
        else:
            self.print_(self.traverse(ast, isLambda=isLambda))
    self.return_none = rn
