question: public String build ( ) { if ( cachedBuildResult != null ) { return cachedBuildResult ; } StringBuilder str = new StringBuilder ( ) ; str . append ( type ) ; str . append ( '/' ) ; str . append ( subType ) ; if ( parameters != null ) { for ( Entry < String , String > entry : parameters . entrySet ( ) ) { String value = entry . getValue ( ) ; str . append ( "; " ) ; str . append ( entry . getKey ( ) ) ; str . append ( "=" ) ; str . append ( ! matchesToken ( value ) ? quoteString ( value ) : value ) ; } } cachedBuildResult = str . toString ( ) ; return cachedBuildResult ; }
target:  Builds the full media type string which can be passed in the Content-Type header.