# pragma mypy relaxed
from typing import Any, Callable, TypeVar, Generic

T = TypeVar( 'T' )

class traced( Generic[ T ] ):
    indent = 0
    counter = 0

    def __init__( self, f: Callable[ ..., T ] ) -> None:
        self.f = f

    def __call__( self, *args: Any, **kwargs: Any ) -> T:
        traced.counter += 1
        cnt = traced.counter
        if cnt > 1:
            print()
        print( ' ' * traced.indent, self.f.__name__, list( args ), end = '' )
        print( kwargs if len(kwargs) else '', end = '' )
        traced.indent += 2
        r = self.f( *args, **kwargs )
        traced.indent -= 2
        if cnt != traced.counter:
            print( '\n' + ' ' * traced.indent, "returned", r )
        else:
            print( ' ->', r, end = '' )
        return r

import run_tests