private static @Nullable String getDocCommentPlaceholderText(@NotNull Document document,
                                                               @NotNull CodeDocumentationAwareCommenter commenter,
                                                               @NotNull TextRange commentRange,
                                                               @NotNull String replacement) {
    final String prefix = commenter.getDocumentationCommentPrefix();
    final String suffix = commenter.getDocumentationCommentSuffix();
    final String linePrefix = commenter.getDocumentationCommentLinePrefix();

    if (prefix == null || suffix == null || linePrefix == null) return null;

    final String header = getCommentHeader(document, suffix, prefix, linePrefix, commentRange);
    final String fullText = getCommentText(document, suffix, prefix, linePrefix, commentRange);
    if (StringUtil.equalsIgnoreWhitespaces(header, fullText)) replacement = "";

    return getCommentPlaceholder(prefix, suffix, header, replacement);
  }
private static @Nullable String getDocCommentPlaceholderText(@NotNull Document document,
                                                               @NotNull CodeDocumentationAwareCommenter commenter,
                                                               @NotNull TextRange commentRange,
                                                               @NotNull String replacement)