code: function parseAnimationClip( xml ) {
  
              var data = {
                  name: xml.getAttribute( 'id' ) || 'default',
                  start: parseFloat( xml.getAttribute( 'start' ) || 0 ),
                  end: parseFloat( xml.getAttribute( 'end' ) || 0 ),
                  animations: []
              };
  
              for ( var i = 0, l = xml.childNodes.length; i < l; i++ ) {
  
                  var child = xml.childNodes[ i ];
  
                  if ( child.nodeType !== 1 ) continue;
  
                  switch ( child.nodeName ) {
  
                      case 'instance_animation':
                          data.animations.push( parseId( child.getAttribute( 'url' ) ) );
                          break;
  
                  }
  
              }
  
              library.clips[ xml.getAttribute( 'id' ) ] = data;
  
          }
docs: animation clips