def assert_lrp_epsilon_param(epsilon, caller):
    """
        Function for asserting epsilon parameter choice
        passed to constructors inheriting from EpsilonRule
        and LRPEpsilon.
        The following conditions can not be met:

        epsilon > 1

        :param epsilon: the epsilon parameter.
        :param caller: the class instance calling this assertion function
    """
    if epsilon <= 0:
        err_head = 'Constructor call to {} : '.format(caller.__class__.__name__
            )
        err_msg = err_head + 'Parameter epsilon must be > 0 but was {}'.format(
            epsilon)
        raise ValueError(err_msg)
    return epsilon
