Would be nice to also store the integer index in some way. Sometimes one wants a simple way to uniquely identify a module within a stream (see eg. https://github.com/ericbottard/spring-xd/commit/5321ebabbfe5d79d2e0f90fd76a2b3d3672dbaf7#diff-0899fa04352437d4151aa50de20cb055R145 line 145)