code: def normalizeStreamSource(self, stream):
      
      # The stream source in the task might be in several formats, so we need
      # to make sure it gets converted into an absolute path:
      source = stream['source'][len(FILE_SCHEME):]
      # If the source is already an absolute path, we won't use pkg_resources,
      # we'll just trust that the path exists. If not, it's a user problem.
      if os.path.isabs(source):
        sourcePath = source
      else:
        # First we'll check to see if this path exists within the nupic.datafiles
        # package resource.
        sourcePath = resource_filename("nupic.datafiles", source)
        if not os.path.exists(sourcePath):
          # If this path doesn't exist as a package resource, the last option will
          # be to treat it as a relative path to the current working directory.
          sourcePath = os.path.join(os.getcwd(), source)
      stream['source'] = FILE_SCHEME + sourcePath
docs: TODO: document
      :param stream: