import dis

let template = '''
class Foo:
    def method(__args__):
        pass
'''

# 'self' can only be the first argument
try:
    dis.build(template.replace('__args__','a,self'))
    print('fail')
except SyntaxError as e:
    print('pass' if 'implicit' in str(e) else 'fail')

# 'self' can not be a star arg
try:
    dis.build(template.replace('__args__','a,*self'))
    print('fail')
except SyntaxError as e:
    print('pass' if 'implicit' in str(e) else 'fail')

# 'self' can not be a star-star arg
try:
    dis.build(template.replace('__args__','a,**self'))
    print('fail')
except SyntaxError as e:
    print('pass' if 'implicit' in str(e) else 'fail')

# 'self' can not take a default value
try:
    dis.build(template.replace('__args__','self=42'))
    print('fail')
except SyntaxError as e:
    print('pass' if 'default argument' in str(e) else 'fail')

# for that matter, neither can star args
try:
    dis.build(template.replace('__args__','*args=[]'))
    print('fail')
except SyntaxError as e:
    print('pass' if 'end of' in str(e) else 'fail')

try:
    dis.build(template.replace('__args__','**args=[]'))
    print('fail')
except SyntaxError as e:
    print('pass' if 'end of' in str(e) else 'fail')