code: private ChmEntry findEntry(String file) {
          for (ChmEntry entry : entries) {
              if (file.equals(entry.getSourcePath())) {
                  return entry;
              }
          }
  
          return null;
      }
docs: Returns the chm entry that references the specified file name.
  
  @param file A file name.
  @return The CHMEntry referencing the specified file, or null if not found.