@NotNull
  public static LineFragment createLineFragment(int startLine1, int endLine1,
                                                int startLine2, int endLine2,
                                                @NotNull LineOffsets lineOffsets1,
                                                @NotNull LineOffsets lineOffsets2) {
    IntPair offsets1 = getOffsets(lineOffsets1, startLine1, endLine1);
    IntPair offsets2 = getOffsets(lineOffsets2, startLine2, endLine2);
    return new LineFragmentImpl(startLine1, endLine1, startLine2, endLine2,
                                offsets1.first, offsets1.second, offsets2.first, offsets2.second);
  }
@NotNull
  public static LineFragment createLineFragment(int startLine1, int endLine1,
                                                int startLine2, int endLine2,
                                                @NotNull LineOffsets lineOffsets1,
                                                @NotNull LineOffsets lineOffsets2)