Why could I be experiencing an unresolved reference error in Python?

Unresolved reference error with the code below; I've included all the references in the same file, however, I'm still getting an error

class sample:
  @staticmethod
  def some_method():
    print("Hello World")
  @staticmethod
  def some_method2():
     some_method()

It's a static method so you need to reference it by the class in front as so:

class sample:

  @staticmethod
  def some_method():
      print("Hello World")

  @staticmethod
  def some_method2():
      sample.some_method()