public void testEvaluateLightFunction() throws IOException {
SBMLDocument light = libsbml.readSBML(Light.getAbsolutePath());
Model m = light.getModel();
ListOfFunctionDefinitions lofd = m.getListOfFunctionDefinitions();
for (long i = 0; i < lofd.size(); i++) {
FunctionDefinition fd = lofd.get(i);
ASTNode root = convertSBMLMathToJavaMath(fd.getMath());
System.err.println(new FormulaFormatter().formulaToString(root));
// over each timestep
for (double step = 0.1; step < 100; step += 0.5) {