| Allow a keyword arg to be specified either as a keyword or a boolean.    This arg type is the most flexible way to allow keyword parameters
    to be specified.  Say there is an option like fontsizethat can
    take the valuessmallorlarge.  This could be represented as         KeywordOrBooleanArg(options=["small", "large"], argname="fontsize")     In that case, the fontsize could be specified in any of the
    following ways:         g.hardcopy(..., fontsize="small", ...)g.hardcopy(..., fontsize="large", ...)g.hardcopy(..., small=1, ...)g.hardcopy(..., large=1, ...)     If argnameis set to beNone, then the first two possibilities
    are omitted.     In the special case that there are exactly two alternatives, one
    can also use:         g.hardcopy(..., small=0, ...) # implies fontsize="large"g.hardcopy(..., large=0, ...) # implies fontsize="small"     Obviously care must be taken to ensure that none of the implied
    keyword parameter names conflict with one another or with any of
    the other Args allowed by a function.     Members:
        optionsa list of strings representing allowed keyword
            values.  These options can be used as boolean values in
            the style option=1.        argnamethe name of the argname for the arg=valuestyle
            of setting the argument.  IfNone, then this style is
            not allowed.        fixedworda fixed keyword that must precede the option,
            or None.        defaultthe default option to set if nothing is set
            explicitly, or None to leave nothing set in that case. 
        
            | Methods |  |  
        | __call__ __init__
 
 |  
            |  | __call__ |  
        | 
__call__ ( self,  keyw )
 
        
            | Exceptions |  |  
        | Errors.OptionError('Arguments %s and %s are contradictory' %( self.argname, k, ) ) Errors.OptionError('Arguments %s and %s cannot both be specified' %( option, k, ) )
 Errors.OptionError('Illegal option %s=%s' %( self.argname, k, ) )
 
 |  |  
            |  | __init__ |  
        | 
__init__ (
        self,
        options,
        argname=None,
        fixedword=None,
        default=None,
        )
 |  |