message: Fixed errors trying to get Medley sample running
diff: @@ -16,14 +16,14 @@ class Motion extends React.Component {
  }
  move() {
  this.setState(({items: prevItems, update}) => {
  - var {data, enter, leave, getKey, onRest} = this.props;
  + var {data, enter, leave, update, getKey, onRest} = this.props;
  var dataByKey = data.reduce((acc, item) => ({...acc, [getKey(item)]: item}), {});
  - var itemsByKey = items.reduce((acc, item) => ({...acc, [item.key]: item}), {});
  + var itemsByKey = prevItems.reduce((acc, item) => ({...acc, [item.key]: item}), {});
  var tick = performance.now();
  var items = prevItems
  .map(item => {
  var end = !dataByKey[item.key] ? leave(item.data) : update(item.data);
  - var equal = areEqual(item.end, end);
  + var equal = this.areEqual(item.end, end);
  var rest = item.progress === 1;
  var progress = equal ? Math.max(Math.min((tick - item.tick) / 500, 1), 0) : 0;
  var interpolators = equal ? item.interpolators : this.getInterpolators(item.style, end);
  @@ -33,14 +33,14 @@ class Motion extends React.Component {
  }
  return {key: item.key, data: item.data, style, end, interpolators, progress, tick, rest};
  })
  - filter(item => !item.rest || dataByKey[item.key])
  + .filter(item => !item.rest || dataByKey[item.key])
  .concat(data
  .filter(item => !itemsByKey[getKey(item)])
  .map(item => {
  var style = enter(item);
  var end = update(item);
  var interpolators = this.getInterpolators(style, end);
  - return {key: getKey(data), data: item, style, end, interpolators, progress: 0, tick, rest: false};
  + return {key: getKey(item), data: item, style, end, interpolators, progress: 0, tick, rest: false};
  })
  );
  this.moveId = requestAnimationFrame(this.move);
  @@ -71,7 +71,7 @@ class Motion extends React.Component {
  return style;
  }
  render() {
  - this.props.children(this.state.items);
  + return this.props.children(this.state.items);
  }
  }
  