class_docstr: A list of files built by on exploring the filesystem and filtered by
  applying various patterns to what we find there.
  
  Instance attributes:
    dir
      directory from which files will be taken -- only used if
      'allfiles' not supplied to constructor
    files
      list of filenames currently being built/filtered/manipulated
    allfiles
      complete list of files under consideration (ie. without any
      filtering applied)
code: def sort(self):
      # Not a strict lexical sort!
      sortable_files = sorted(map(os.path.split, self.files))
      self.files = []
      for sort_tuple in sortable_files:
          self.files.append(os.path.join(*sort_tuple))
  
imports: import os, re
  import fnmatch
  import functools
  from distutils.util import convert_path
  from distutils.errors import DistutilsTemplateError, DistutilsInternalError
  from distutils import log
label_desc: Use image node_id 7 for calling the FileList obj's underlying member method code with example usage: obj.sort() without return types