code: function _serveFile(requestedFile, done) {
          let compiled
              , temp = []
              , wasCompiled;
  
          log.debug(`Fetching ${transformPath(requestedFile.path)} from buffer`);
  
  
          if (requestedFile.sha) {
              delete requestedFile.sha; //simple hack i used to prevent infinite loop
              _feedBuffer(requestedFile, done);
              compile();
              return;
          }
  
          while (compiled = _compiledBuffer.shift()) {
              if (_normalize(compiled.path) === _normalize(requestedFile.path)) {
                  wasCompiled = true;
                  done(null, compiled.contents.toString());
              } else {
                  temp.unshift(compiled);
              }
          }
  
          //refeed buffer
          _compiledBuffer = temp;
  
          //if file was not found in the stream
          //maybe it is not compiled or it is a definition file, so we don't need to worry about
          if (!wasCompiled) {
              log.debug(`${requestedFile.originalPath} was not found. Maybe it was not compiled or it is a definition file.`);
              done(null, dummyFile("This file was not compiled"));
          }
      }
docs: Used to fetch files from buffer if requested file contains a sha defined, it means this file was changed by karma