code: public JBBPTextWriter SetHR(final String prefix, final int length, final char ch) {
      this.prefixHR = prefix == null ? "" : prefix;
      this.hrChar = ch;
      this.hrLength = length;
      return this;
    }
docs: Change parameters for horizontal rule.
  
  @param prefix the prefix to be printed before rule, it can be null
  @param length the length in symbols.
  @param ch     symbol to draw
  @return the context