public void setExtractAllAlternatives(boolean extractAllAlternatives) {
        this.extractAllAlternatives = extractAllAlternatives;
    }
Until version 1.17, Tika handled all body parts as embedded objects (see TIKA-2478).
In 1.17, we modified the parser to select only the best alternative body
parts for multipart/alternative sections, and we inline the content
as we do for .msg files.
<p>
The legacy behavior can be set by setting {@link #extractAllAlternatives}
to <code>true</code>.  As of 1.17, the default value is <code>false</code>

@param extractAllAlternatives whether or not to extract all alternative parts
@since 1.17
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-mail-module/src/main/java/org/apache/tika/parser/mail/RFC822Parser.java