code: async function () {
      const oThis = this
      ;
  
      //Validations
      if (!basicHelper.isAddressValid(oThis.erc20Address)) {
        let errObj = responseHelper.error({
          internal_error_identifier: 's_a_bt_2',
          api_error_identifier: 'invalid_address',
          error_config: basicHelper.fetchErrorConfig()
        });
  
        return Promise.reject(errObj);
      }
  
      if (!basicHelper.isAddressValid(oThis.approverAddress)) {
        let errObj = responseHelper.error({
          internal_error_identifier: 's_a_bt_3',
          api_error_identifier: 'invalid_address',
          error_config: basicHelper.fetchErrorConfig()
        });
  
        return Promise.reject(errObj);
      }
  
      if (oThis.toApproveAmount.lessThan(0)) {
        let errObj = responseHelper.error({
          internal_error_identifier: 's_a_bt_4',
          api_error_identifier: 'invalid_amount',
          error_config: basicHelper.fetchErrorConfig()
        });
  
        return Promise.reject(errObj);
      }
  
      return Promise.resolve(responseHelper.successWithData({}));
    }
docs: Validate
  
  @return {promise<result>}
  @private
  @ignore