fixed a bug in useful_functions.
fixed a bug in useful_functions.
ananda621/rl-glue,cameron-upright/rl-glue,cosmoharrigan/rl-glue,ananda621/rl-glue,cameron-upright/rl-glue,cosmoharrigan/rl-glue,davidljung/rl-glue,davidljung/rl-glue