human
Solve the following python programming problem given the following code:
def coerce(from_, to, **to_kwargs) : 
    "
    A preprocessing decorator that coerces inputs of a given type by passing
    them to a callable.

    Parameters
    ----------
    from : type or tuple or types
        Inputs types on which to call ``to``.
    to : function
        Coercion function to call on inputs.
    **to_kwargs
        Additional keywords to forward to every call to ``to``.

    Usage
    -----
    >>> @preprocess(x=coerce(float, int), y=coerce(float, int))
    ... def floordiff(x, y):
    ...     return x - y
    ...
    >>> floordiff(3.2, 2.5)
    1

    >>> @preprocess(x=coerce(str, int, base=2), y=coerce(str, int, base=2))
    ... def add_binary_strings(x, y):
    ...     return bin(x + y)[2:]
    ...
    >>> add_binary_strings('101', '001')
    '110'
    " 
    def preprocessor(func, argname, arg) : 
        if isinstance (arg, from_) : 
            return to (arg, ** to_kwargs) 
return arg 
return to_kwargs 

    
    

    Fix the buggy line: return to_kwargs
assistant
#Here is Python program to fix the buggy line: return to_kwargs
.

return def preprocessor(