in spec/command_tests/helpers.ts [63:74]
(driver as any)[commandName] = function() {
let oldCount = spy.calls.count();
return oldFun.apply(this, arguments).then((result: any) => {
expect(spy.calls.count()).toBe(oldCount + 1);
let args = spy.calls.mostRecent().args;
return {
result: result,
session: args[0],
params: args[1]
};
});
};