code: function endStream(cb) {
          // If no files were passed in, no files go out ...
          if (!latestFile || (Object.keys(concats).length === 0 && concats.constructor === Object)) {
              cb();
              return;
          }
  
          // Prepare a method for pushing the stream
          const pushJoinedFile = (joinedBase) => {
              const joinedFile = new File({
                  path: joinedBase,
                  contents: concats[joinedBase].concat.content,
                  stat: concats[joinedBase].stats
              });
              if (concats[joinedBase].concat.sourceMapping) {
                  joinedFile.sourceMap = JSON.parse(concats[joinedBase].concat.sourceMap);
              }
              this.push(joinedFile);
              delete concats[joinedBase];
          };
  
          // Refine the dependency graph
          const refinedDependencyMap = [];
          dependencyGraph.forEach(edge => {
              if ((edge[0] in nameBaseMap) && (edge[1] in nameBaseMap)) {
                  refinedDependencyMap.push([nameBaseMap[edge[0]], nameBaseMap[edge[1]]]);
              }
          });
          const sortedDependencies = refinedDependencyMap.length ? toposort(refinedDependencyMap).reverse() : [];
          sortedDependencies.map(pushJoinedFile);
  
          // Run through all registered contact instances
          for (const targetBase in concats) {
              pushJoinedFile(targetBase);
          }
          cb();
      }
docs: End the stream
  
  @param {Function} cb Callback