Take a look at the example_usage.py too. Take note that all the functions exist inside a class called DynamicPygameGraphs. Essentially you need to first make an instance of this class with details ...

The call f(x) has a side-effect on x if f updates a field (x.m = y), updates an element (x[i] = y), updates a global variable, or transitively calls another function that has a side effect. Rather ...