@staticmethod
def classification_function_zero(size, color, shape):
    """ classification_function_zero

        Decides the sample class label as positive if the color is red and
        size is small.

        Parameters
        ----------
        size: int
            First numeric attribute.

        color: int
            Second boolean attribute.

        shape: int
            Third boolean attribute

        Returns
        -------
            int
            Returns the sample class label, either 0 or 1.

               """
    return 1 if size == 0 and color == 0 else 0
