code: def remove_entity_headers(headers, allowed=("expires", "content-location")):
      
      allowed = set(x.lower() for x in allowed)
      headers[:] = [
          (key, value)
          for key, value in headers
          if not is_entity_header(key) or key.lower() in allowed
      ]
docs: Remove all entity headers from a list or :class:`Headers` object.  This
      operation works in-place.  `Expires` and `Content-Location` headers are
      by default not removed.  The reason for this is :rfc:`2616` section
      10.3.5 which specifies some entity headers that should be sent.
  
      .. versionchanged:: 0.5
         added `allowed` parameter.
  
      :param headers: a list or :class:`Headers` object.
      :param allowed: a list of headers that should still be allowed even though
                      they are entity headers.