'Generate an "exclusion string" for the given option
@type longname: C{str}
@param longname: The long option name (e.g. "verbose" instead of "v")
@type buildShort: C{bool}
@param buildShort: May be True to indicate we\'re building an excludes
string for the short option that corresponds to the given long opt.
@return: The generated C{str}'

def excludeStr(self, longname, buildShort=False):

    if (longname in self.excludes):
        exclusions = self.excludes[longname].copy()
    else:
        exclusions = set()
    if (longname not in self.multiUse):
        if (buildShort is False):
            short = self.getShortOption(longname)
            if (short is not None):
                exclusions.add(short)
        else:
            exclusions.add(longname)
    if (not exclusions):
        return ''
    strings = []
    for optName in exclusions:
        if (len(optName) == 1):
            strings.append(('-' + optName))
        else:
            strings.append(('--' + optName))
    strings.sort()
    return ('(%s)' % '    '.join(strings))
