code: function addOrigin ( base, handleNumber ) {
  
              var origin = addNodeTo(base, options.cssClasses.origin);
              var handle = addNodeTo(origin, options.cssClasses.handle);
              addNodeTo(handle, options.cssClasses.handleTouchArea);
  
              handle.setAttribute('data-handle', handleNumber);
  
              if ( handleNumber === 0 ) {
                  addClass(handle, options.cssClasses.handleLower);
              }
  
              else if ( handleNumber === options.handles - 1 ) {
                  addClass(handle, options.cssClasses.handleUpper);
              }
  
              return origin;
          }
docs: Append a origin to the base