input: Write a function to check if two integers are equal. The function should take two integers as input and return True if they are equal, and False otherwise. If either of the inputs is not an integer, the function should return an error message.
  
  def check_equality(int1, int2):
      if not isinstance(int1, int) or not isinstance(int2, int):
          return "Invalid input: Both inputs must be integers."
      return int1 == int2
  
  assert check_equality(10, 10) == True
  assert check_equality(3, 5) == False
  assert check_equality(7, "7") == "Invalid input: Both inputs must be integers."
  assert check_equality("a", 5) == "Invalid input: Both inputs must be integers."
output: def check_equality(int1, int2):
      if not isinstance(int1, int) or not isinstance(int2, int):
          return "Invalid input: Both inputs must be integers."
      return int1 == int2