Check whether the given function is a lambda function.

    .. testsetup::

        from proso.func import is_lambda

    .. testcode::

        def not_lambda_fun():
            return 1

        lambda_fun = lambda: 1

        print(
            is_lambda(not_lambda_fun),
            is_lambda(lambda_fun)
        )
    .. testoutput::

        False True

    Args:
        fun (function)

    Returns:
        bool: True if the given function is a lambda function, False otherwise

def is_lambda(fun):
    """
    Check whether the given function is a lambda function.

    .. testsetup::

        from proso.func import is_lambda

    .. testcode::

        def not_lambda_fun():
            return 1

        lambda_fun = lambda: 1

        print(
            is_lambda(not_lambda_fun),
            is_lambda(lambda_fun)
        )
    .. testoutput::

        False True

    Args:
        fun (function)

    Returns:
        bool: True if the given function is a lambda function, False otherwise
    """
    return isinstance(fun, type(LAMBDA)) and fun.__name__ == LAMBDA.__name__