docstr: Helper to generate custom datalad URL prefixes
          
docstr_tok: ["Helper","to","generate","custom","datalad","URL","prefixes"]
code: def _get_custom_scheme(cls, prefix):
      """Helper to generate custom datalad URL prefixes"""
      # prefix which will be used in all URLs supported by this custom remote
      # https://tools.ietf.org/html/rfc2718 dictates "URL Schemes" standard
      # 2.1.2 suggests that we do use // since all of our URLs will define
      # some hierarchical structure.  But actually since we might encode
      # additional information (such as size) into the URL, it will not be
      # strictly conforming it. Thus we will not use //
      return "%s+%s" % (URI_PREFIX, prefix)
  
file_path: datalad/datalad/customremotes/base.py
imports: from __future__ import absolute_import
  import logging
  from collections import Counter
  from annexremote import RemoteError, UnsupportedRequest
  from datalad.customremotes import SpecialRemote
label_desc: Use image node_id 2 for calling the AnnexCustomRemote obj's underlying member method code with example usage: obj._get_custom_scheme(cls, prefix) and returns: unknown