docs: function removeEmptyInlines ( root ) {
      var children = root.childNodes,
          l = children.length,
          child;
      while ( l-- ) {
          child = children[l];
          if ( child.nodeType === ELEMENT_NODE && !isLeaf( child ) ) {
              removeEmptyInlines( child );
              if ( isInline( child ) && !child.firstChild ) {
                  root.removeChild( child );
              }
          } else if ( child.nodeType === TEXT_NODE && !child.data ) {
              root.removeChild( child );
          }
      }
  }