code: public static byte createTag(byte tagClass, boolean form, byte val) {
          byte tag = (byte)(tagClass | val);
          if (form) {
              tag |= (byte)0x20;
          }
          return (tag);
      }
docs: Create the tag of the attribute.
  
  @params class the tag class type, one of UNIVERSAL, CONTEXT,
  APPLICATION or PRIVATE
  @params form if true, the value is constructed, otherwise it
  is primitive.
  @params val the tag value