input: Write a function that lists the contents of a specified directory. The function should take a directory path as input and return a list of filenames and directories contained within that directory.
  assert list_directory_contents("C:\\Users\\John\\Documents") == ['file1.txt', 'file2.txt', 'folder1']
  assert list_directory_contents("/home/user/pictures") == ['photo1.jpg', 'photo2.jpg', 'vacation']
  assert list_directory_contents("/tmp") == ['tempfile1', 'tempfile2']
output: import os
  
  def list_directory_contents(directory_path):
      return os.listdir(directory_path)