    """Common globals.

    The Common module provides some commmon globals to all modules/classes in
    WebKit. It's intended for internal use, not for modules outside the WebKit.

    Typically usage is::

        from Common import *

    The globals provided are:
    * the modules: `os`, `sys`, `time`
    * the class `StringIO`
    * the root class `Object`
    * the names `True` and `False` for older Python versions
    * the package `WebUtils`
    * the exception class `AbstractError` that methods of abstract classes can raise
    * the singleton `NoDefault`  for initializing default arguments
    * the method `asclocaltime` for building time stamps in log files

    """

    import os, sys, time

    try: # for Python < 2.3
        True, False
    except NameError:
        True, False = 1, 0

    from Object import Object
    import WebUtils
    from MiscUtils import StringIO, AbstractError, NoDefault

    def asclocaltime(t = None):
        """Return a readable string of the current, local time.

        Useful for time stamps in log files.

        """
        if t is None:
            t = time.time()
        return time.asctime(time.localtime(t))