question: public StrBuilder replaceAll ( String searchStr , String replaceStr ) { int searchLen = ( searchStr == null ? 0 : searchStr . length ( ) ) ; if ( searchLen > 0 ) { int replaceLen = ( replaceStr == null ? 0 : replaceStr . length ( ) ) ; int index = indexOf ( searchStr , 0 ) ; while ( index >= 0 ) { replaceImpl ( index , index + searchLen , searchLen , replaceStr , replaceLen ) ; index = indexOf ( searchStr , index + replaceLen ) ; } } return this ; }
target:  Replaces the search string with the replace string throughout the builder.