@Nullable
  private static JComponent createTitle(@Nullable @NlsContexts.Label String title,
                                        @NotNull DiffContent content,
                                        boolean equalCharsets,
                                        boolean equalSeparators,
                                        @Nullable Editor editor,
                                        @Nullable DiffEditorTitleCustomizer titleCustomizer) {
    if (content instanceof EmptyContent) return null;
    DocumentContent documentContent = (DocumentContent)content;

    Charset charset = equalCharsets ? null : documentContent.getCharset();
    Boolean bom = equalCharsets ? null : documentContent.hasBom();
    LineSeparator separator = equalSeparators ? null : documentContent.getLineSeparator();
    boolean isReadOnly = editor == null || editor.isViewer() || !canMakeWritable(editor.getDocument());

    return createTitle(title, separator, charset, bom, isReadOnly, titleCustomizer);
  }
@Nullable
  private static JComponent createTitle(@Nullable @NlsContexts.Label String title,
                                        @NotNull DiffContent content,
                                        boolean equalCharsets,
                                        boolean equalSeparators,
                                        @Nullable Editor editor,
                                        @Nullable DiffEditorTitleCustomizer titleCustomizer)