lib/index.js
function(language){
    var browserLocale = navigator.language || navigator.userLanguage || navigator.browserLanguage;
    this.options.language = language || this.options.language || browserLocale;
    return this;
  }
function(language){
    var browserLocale = navigator.language || navigator.userLanguage || navigator.browserLanguage;
    this.options.language = language || this.options.language || browserLocale;
    return this;
  }
function ( language ) { var browserLocale = navigator . language || navigator . userLanguage || navigator . browserLanguage ; this . options . language = language || this . options . language || browserLocale ; return this ; }
Get the language to use in UI elements and when making search requests

Look first at the explicitly set options otherwise use the browser's language settings
@param {String} language Specify the language to use for response text and query result weighting. Options are IETF language tags comprised of a mandatory ISO 639-1 language code and optionally one or more IETF subtags for country or script. More than one value can also be specified, separated by commas.
@returns {MapboxGeocoder} this
Get the language to use in UI elements and when making search requests