class_docstr: Base class for the downloaders
class_docstr_tok: ["Base","class","for","the","downloaders"]
docstr: Fetch and return content (not decoded) as pointed by the URL
  
  Parameters
  ----------
  url : string
    URL to access
  
  Returns
  -------
  bytes
    content
docstr_tok: ["Fetch","and","return","content","(","not","decoded",")","as","pointed","by","the","URL","Parameters","--","--","--","--","--","url",":","string","URL","to","access","Returns","--","--","--","-","bytes","content"]
code: def fetch(self, url, **kwargs):
      """Fetch and return content (not decoded) as pointed by the URL
  
      Parameters
      ----------
      url : string
        URL to access
  
      Returns
      -------
      bytes
        content
      """
      lgr.debug("Fetching %r", url)
      # Do not return headers, just content
      out = self.access(self._fetch, url, **kwargs)
      return out[0]
  
imports: import msgpack
  import os
  import sys
  import time
  from abc import ABCMeta, abstractmethod
  import os.path
  from os.path import exists, join, isdir
  from ..None import cfg
  from ..ui import ui
  from ..utils import auto_repr, ensure_unicode, unlink
  from .credentials import CompositeCredential
  from datalad.downloaders import CREDENTIAL_TYPES
  from ..support.exceptions import AccessDeniedError, AccessPermissionExpiredError, AnonymousAccessDeniedError, CapturedException, DownloadError, IncompleteDownloadError, UnaccountedDownloadError
  from ..support.locking import InterProcessLock, try_lock, try_lock_informatively
  from logging import getLogger
label_desc: Use image node_id 13 for calling the BaseDownloader obj's underlying member method code with example usage: obj.fetch(url) and returns: out