text: from importlib import import_module
  
  
  def import_optional_dependency(module_to_import: str, dependency: str = None):
      """
      Attempt to import a module from an external dependency.
      Raise an error if that dependency is not installed.
      Args:
          module_to_import: A string containing the module to be imported
          dependency: Information about the dependency required
      Raises:
          ModuleNotFoundError: If the dependency is not installed
      Examples:
          >>> math = import_optional_dependency('math')
          >>> pyyaml = import_optional_dependency("pyyaml")
          Traceback (most recent call last):
          ...
          ModuleNotFoundError: pyyaml is required to use this function.
      """
      try:
          return import_module(module_to_import)
      except ModuleNotFoundError:
          raise ModuleNotFoundError(f"{dependency or module_to_import} is required to use this function.")
  