input: Write a response that appropriately completes the request.
  
  ### Instruction:
  Construct a class in Python which implements two methods to add two numbers.
  
  ### Input:
  None
  
  ### Output:
  class Calculator:
   def __init__(self):
     pass
      
   def add_two_numbers(self, a, b):
     return a + b
  
   def add(self, a, b, c):
     return a + b + c
  
  calculator = Calculator()
  result = calculator.add_two_numbers(1, 2)
  print(result)
output: class Calculator:
   def __init__(self):
     pass
      
   def add_two_numbers(self, a, b):
     return a + b
  
   def add(self, a, b, c):
     return a + b + c