text: from typing import Optional, Sequence, Tuple
  
  try:
      import httpx
  except ImportError:  # pragma: no cover
      raise Exception(
          'Please run $pip install datamodel-code-generator[http] to resolve URL Reference'
      )
  
  
  def get_body(url: str, headers: Optional[Sequence[Tuple[str, str]]] = None) -> str:
      return httpx.get(url, headers=headers).text
  
  
  def join_url(url: str, ref: str = '.') -> str:
      return str(httpx.URL(url).join(ref))
  