input: 
  from typing import List
  
  def fibonacci(n: int) -> int:
      """ Calculate and return the nth Fibonacci number.
      >>> fibonacci(6)
      8
      >>> fibonacci(10)
      55
      """
      if n == 0:
          return 0
      elif n == 1:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)
  
  
  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