def METHOD_NAME(linter, code, error_type):
    # type: (persist.LinterName, str, str) -> str
    icon = get_value_('icon', linter, code, error_type, 'none')
    if icon in ('circle', 'dot', 'bookmark', 'none'):  # Sublime Text has some default icons
        return icon
    elif icon != os.path.basename(icon):
        return icon
    elif persist.settings.get('gutter_theme').endswith('.gutter-theme'):
        theme_path = os.path.dirname(persist.settings.get('gutter_theme'))
        if not icon.endswith('.png'):
            icon += '.png'
        return '{}/{}'.format(theme_path, icon)
    else:
        theme = persist.settings.get('gutter_theme')
        if not icon.endswith('.png'):
            icon += '.png'
        return 'Packages/SublimeLinter/gutter-themes/{}/{}'.format(theme, icon)