input: Write a function to create a dictionary in Python with given key-value pairs. If the dictionary is successfully created, return the dictionary; otherwise, return None.
  assert create_dict({"FirstName": "John"}) == {"FirstName": "John"}
  assert create_dict({"LastName": "Doe"}) == {"LastName": "Doe"}
  assert create_dict({}) == {}
  assert create_dict({"Age": 30, "Occupation": "Engineer"}) == {"Age": 30, "Occupation": "Engineer"}
  assert create_dict([]) == None
output: def create_dict(pairs):
      if isinstance(pairs, dict):
          return pairs
      else:
          return None