input: Write a python function to remove all whitespace from a given string.
  assert clear_whitespace(" Hello World    ") == "HelloWorld"
  assert clear_whitespace("   Python Programming  ") == "PythonProgramming"
  assert clear_whitespace("   NoSpace  ") == "NoSpace"
output: def clear_whitespace(s: str) -> str:
      return s.replace(" ", "")