renderInitialClones() {
    const { source, target } = this.props;
    const transition = this.getTransition();
    const nativeContentTypeString =
      (transition.defaultProps
        ? transition.defaultProps.nativeContentType
        : undefined) || "children";
    const nativeContentType = contentTypeFromString(nativeContentTypeString);
    return [
      <MagicMoveClone
        key="target0"
        component={target}
        mmContext={target.props.mmContext}
        options={
          MagicMoveClone.Option.INITIAL |
          MagicMoveClone.Option.TARGET |
          (this.isDebug ? MagicMoveClone.Option.DEBUG : 0)
        }
        nativeContentType={nativeContentType}
        onLayout={this.onLayoutTargetClone}
      >
        {target.props.children}
      </MagicMoveClone>,
      <MagicMoveClone
        key="source0"
        component={source}
        mmContext={source.props.mmContext}
        options={
          MagicMoveClone.Option.INITIAL |
          MagicMoveClone.Option.VISIBLE |
          (this.isDebug ? MagicMoveClone.Option.DEBUG : 0)
        }
        nativeContentType={nativeContentType}
        onShow={this.onShowSourceClone}
      >
        {source.props.children}
      </MagicMoveClone>
    ];
  }
Renders the initial clones of the source and
target components. The clones are also responsible
for measuring the layout of the source/target components
and supplying that to this class, so it can start the
transition animation with it.