input: Write a python function to check if the package structure of MyApp is organized correctly.
  assert check_package_structure("myapp") == True
  assert check_package_structure("myapp.controllers") == True
  assert check_package_structure("myapp.nonexistent") == False
output: def check_package_structure(package_name):
      import importlib
      try:
          importlib.import_module(package_name)
          return True
      except ImportError:
          return False