input: Write a function to list the contents of a directory using Python. The function should return a list of strings representing the names of all items in the directory. If the directory is empty, the function should return an empty list.
  assert list_directory_contents("some_folder")==["file1.txt", "file2.txt", "folder1"]
  assert list_directory_contents("empty_folder")==[]
  assert list_directory_contents("nonexistent_folder")==[]
output: import os
  
  def list_directory_contents(directory):
      if not os.path.exists(directory):
          return []
      return os.listdir(directory)