input: Write a Python function to generate Fibonacci numbers up to a given maximum.
  assert fibonacciGenerator(0) == []
  assert fibonacciGenerator(1) == [0]
  assert fibonacciGenerator(10) == [0, 1, 1, 2, 3, 5, 8]
  assert fibonacciGenerator(15) == [0, 1, 1, 2, 3, 5, 8, 13]
output: def fibonacciGenerator(max_value):
      if max_value < 0:
          return []
      fib_list = []
      a, b = 0, 1
      while a <= max_value:
          fib_list.append(a)
          a, b = b, a + b
      return fib_list