text: export const ERROR_TYPE_UNKNOWN = 1;
  export const ERROR_TYPE_INPUT = 2;
  export const ERROR_TYPE_PARSE = 3;
  export const ERROR_VERIFY_SIGNATURE = 4;
  
  class SignPdfError extends Error {
      constructor(msg, type = ERROR_TYPE_UNKNOWN) {
          super(msg);
          this.type = type;
      }
  }
  
  // Shorthand
  SignPdfError.TYPE_UNKNOWN = ERROR_TYPE_UNKNOWN;
  SignPdfError.TYPE_INPUT = ERROR_TYPE_INPUT;
  SignPdfError.TYPE_PARSE = ERROR_TYPE_PARSE;
  SignPdfError.VERIFY_SIGNATURE = ERROR_VERIFY_SIGNATURE;
  
  export default SignPdfError;
  