Initial imports and setup.
---------------------------
    >>> from Products.CMFCore.utils import getToolByName
    >>> from Products.Five.testbrowser import Browser
    >>> browser = Browser()
    >>> portal_url = portal.absolute_url()

Check the supported languages.
------------------------------
    >>> language_tool = getToolByName(portal, 'portal_languages')
    >>> language_tool.getSupportedLanguages()
    ['en', 'ja']
    >>> language_tool.getLanguageBindings()
    ('en', 'en', [])

ILangCharset interface provides language and its charset for the language of the site.
---------------------------------------------------------------------------------------
    >>> from collective.langMailHost.interfaces import ILangCharset
    >>> ILangCharset(portal).lang_charset()
    {'ja': 'iso-2022-jp'}
    >>> ILangCharset(portal).effective_lang()
    'en'
    >>> ILangCharset(portal).effective_charset()
