code: public void setFileName(String filename, String typeName) {
          mSingleFileName = null;
          if (mFileNames == null) {
              mFileNames = new HashMap<String, String>();
          }
          mFileNames.put(typeName, filename);
      }
docs: Specify the file that a BDB database should reside in, except for log
  files and caches. The filename is relative to the environment home,
  unless data directories have been specified. For BDBRepositories that
  are log files only, this configuration is ignored.
  
  @param filename BDB database filename
  @param typeName type to store in file; if null, the file is used by default
  for all types