code: public CSV header(String... items) {
        this.header = (items == null ? null : Arrays.asList(items));
        if (header != null && header.size() > 0) {
           this.hasHeader = true;
        }
        return this;
     }
docs: Specifies the names of the items in the CSV header.
  
  @param items the names of the columns (i.e. header names)
  @return the csv builder