code: function() {
  
              var self = this;
  
              var bsExplanation = '';
              if(self.options.explanationBuilder) {
                  // call customized explanation builder.
                  bsExplanation = 
                      self.options.explanationBuilder(self.attrId);
              } else {
                  bsExplanation = 
                      self.buildDefaultExplanation(self.attrId);
              }
  
              $('body').append(bsExplanation);
          }
docs: append the explanation div and the inline styles for it.
  the option explanationBuilder will be checked to
  allow developer to customize the explanation div
  
  self.options.explanationBuilder(prefix);