input: Write a python function to create a dictionary of programming languages and their abbreviations, then print each key-value pair.
  assert print_languages() == "C: c\nC++: cpp\nPython: py\nJava: java\nC#: cs\nJavaScript: js\nPHP: php\nRust: rs\nSwift: swift\nGo: go\n"
output: def print_languages():
      languages = {
          "C": "c",
          "C++": "cpp",
          "Python": "py",
          "Java": "java",
          "C#": "cs",
          "JavaScript": "js",
          "PHP": "php",
          "Rust": "rs",
          "Swift": "swift",
          "Go": "go"
      }
      
      result = []
      for lang, abbr in languages.items():
          result.append(f"{lang}: {abbr}")
      
      return "\n".join(result)