code: function getFieldsFromTweetLike(tweetLike) {
    var fields = fieldsToCheck.map(function(fieldName) {
      return _.get(tweetLike, fieldName);
    });
  
    arrayFieldsToCheck.forEach(function(fieldDescription) {
      var arr = _.get(tweetLike, fieldDescription.arrayAt);
      if (_.isArray(arr)) {
        arr.forEach(function(element) {
          fields.push(_.get(element, fieldDescription.inEach));
        });
      }
    });
  
    return fields.filter(function(field) {
      return typeof field === 'string' && field.trim().length !== 0;
    }).map(function(field) {
      return field.toLowerCase();
    });
  }
docs: Takes a tweet or a subobject of tweet and looks for strings in the positions listed in fieldsToCheck and arrayFieldsToCheck