input: Write a function to calculate the compound interest based on the given investment amount, rate of interest, and time. The function should return the calculated compound interest. If the input parameters are invalid (e.g., negative values for investment amount, rate of interest, or time), the function should return `None`.
  
  def compoundInterest(investment_amount, rate_of_interest, time):
      if investment_amount < 0 or rate_of_interest < 0 or time < 0:
          return None
      compound_interest = investment_amount * (pow((1 + rate_of_interest / 100), time))
      return compound_interest
  
  assert compoundInterest(1000, 5, 5) == 1276.2815625000003
  assert compoundInterest(2000, 6, 3) == 2382.032
  assert compoundInterest(500, 3, 7) == 614.9003840375002
  assert compoundInterest(1000, -5, 5) == None
  assert compoundInterest(-1000, 5, 5) == None
  assert compoundInterest(1000, 5, -5) == None
  assert compoundInterest(0, 0, 0) == 0
output: def compoundInterest(investment_amount, rate_of_interest, time):
      if investment_amount < 0 or rate_of_interest < 0 or time < 0:
          return None
      compound_interest = investment_amount * (pow((1 + rate_of_interest / 100), time))
      return compound_interest