input: 
  def determine_commission_rate(gross_sales: float) -> float:
      """Return the commission rate based on the gross sales amount.
      The commission rate is 0.1 for sales >= 10000,
      0.07 for sales >= 5000 and < 10000,
      and 0.05 for sales < 5000.
      
      >>> determine_commission_rate(12000)
      0.1
      >>> determine_coursecommission_rate(7500)
      0.07
      >>> determine_commission_rate(3000)
      0.05
      """
      if gross_sales >= 10000:
          return 0.1
      elif gross_sales >= 5000:
          return 0.07
      else:
          return 0.02
  
  from typing import List
  
  
  def has_close_elements(numbers: List[float], threshold: float) -> bool:
      """ Check if in given list of numbers, are any two numbers closer to each other than
      given threshold.
      >>> has_close_elements([1.0, 2.0, 3.0], 0.5)
      False
      >>> has_close_elements([1.0, 2.8, 3.0, 4.0, 5.0, 2.0], 0.3)
      True
      """
  
output:     
      for i in range(len(numbers)):
          for j in range(i + 1, len(numbers)):
              if abs(numbers[i] - numbers[j]) < threshold:
                  return True
      return False
  