docs: @Override
      protected void encode() {
  
          if (!content.matches("[A-D]{1}[0-9:/\\$\\.\\+\u002D]+[A-D]{1}")) {
              throw new OkapiException("Invalid characters in input");
          }
  
          String horizontalSpacing = "";
  
          int l = content.length();
          for (int i = 0; i < l; i++) {
               horizontalSpacing += CODABAR_TABLE[positionOf(content.charAt(i), CHARACTER_SET)];
          }
  
          readable = content;
          pattern = new String[] { horizontalSpacing };
          row_count = 1;
          row_height = new int[] { -1 };
      }