code: public boolean addSourceDirs(Collection<String> sourceDirs) {
          boolean isNew = false;
  
          if (sourceDirs == null || sourceDirs.isEmpty()) {
              return isNew;
          }
  
          for (String dirName : sourceDirs) {
              for (String dir : makeAbsoluteCwdCandidates(dirName)) {
                  isNew = addToListInternal(srcDirList, dir) || isNew;
              }
          }
          IO.close(sourceFinder);
          sourceFinder = new SourceFinder(this);
          return isNew;
      }
docs: Add source directories to the project.
  
  @param sourceDirs
  The source directories to add. These can be either absolute paths
  or relative to any of the working directories in this project object.
  @return true if a source directory was added or false if all source
  directories were already present