function runWithDebugger(callback, args) {
  debugger;
  if (Array.isArray(args)){
    callback(...args);
  }
  else {
    callback(args);
  }
}

function sayHi() {
  console.log('Hi');
}
function sayHiTo(name) {
  console.log('hi ' + name);
}
function sayFullName(first, last) {
  console.log(first + ' '  + last);
}

console.log('testing without any arguments');
runWithDebugger(sayHi);                             // 'Hi'
console.log('Testing sayHiTo with string input:');
runWithDebugger(sayHiTo, 'gordon');                 // 'Hi gordon'
console.log('Testing sayHiTo Array one item:');
runWithDebugger(sayHiTo, ['gordon']);               // 'Hi gordon''
console.log('Testing sayFullName Array multiple items:');
runWithDebugger(sayFullName, ['gordon', 'zhu']);    // 'gordon zhu'