input: Write a python function to calculate monthly payment for a loan.
  assert calculate_monthly_payment(2000, 0.10, 3) == 64.82
  assert calculate_monthly_payment(5000, 0.05, 5) == 94.36
  assert calculate_monthly_payment(10000, 0.07, 10) == 116.11
output: def calculate_monthly_payment(principal, annual_interest_rate, years):
      monthly_interest_rate = annual_interest_rate / 12
      number_of_payments = years * 12
      numerator = principal * monthly_interest_rate * (1 + monthly_interest_rate) ** number_of_payments
      denominator = (1 + monthly_interest_rate) ** number_of_payments - 1
      monthly_payment = numerator / denominator
      return round(monthly_payment, 2)