code: function collectFlows( entries ) {
        const followFlowOnce = promiseOnce( followFlow );
        const followEntryToFlows = followEntryRefs( 'flows', followFlowOnce );
  
        return Promise.all( entries.map( followEntryToFlows ) )
           .then( flatten )
           .then( dedupe );
     }
docs: //////////////////////////////////////////////////////////////////////////////////////////////////////// 
  Asynchronously collect all flows corresponding to the given refs.
  
  Example:
  
  collector.collectFlows( [ { flows: [ 'flow' ] } ] )
  .then( flows => {
  assert( Array.isArray( flows ) );
  } );
  // => [ {
  //       refs: [ 'flow' ],
  //       name: 'flow',
  //       path: 'path/to/flow.json',
  //       pages: [ ... ]
  //    } ]
  
  
  @memberOf ArtifactCollector
  @param {Array} entries a list of entry objects containing a flows key
  @return {Promise<Array>}
  a promise for an array of flow-meta objects