def concrete_descendents(parentclass):
    """
    Return a dictionary containing all subclasses of the specified
    parentclass, including the parentclass.  Only classes that are
    defined in scripts that have been run or modules that have been
    imported are included, so the caller will usually first do ``from
    package import *``.

    Only non-abstract classes will be included.
    """
    return dict((c.__name__,c) for c in descendents(parentclass)
                if not _is_abstract(c))
Return a dictionary containing all subclasses of the specified
    parentclass, including the parentclass.  Only classes that are
    defined in scripts that have been run or modules that have been
    imported are included, so the caller will usually first do ``from
    package import *``.

    Only non-abstract classes will be included.