protected void setNum_blocks(long num_blocks) {
        this.num_blocks = num_blocks;
    }
Sets number of blocks containing in the chm file

@param num_blocks
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/chm/ChmItspHeader.java