<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def call_fn_name(token):
 """Customize CALL_FUNCTION to add the number of positional arguments"""

        if token.attr is not None:
            return '%s_%i' % (token.kind, token.attr)
        else:
            return '%s_0' % (token.kind)