# getFieldExtension method

Extension? getFieldExtension()

Gets the the field extension.

return The field extension. throws BiosealException An error has occurred during Bioseal Library execution.

## Implementation

    Extension? getFieldExtension() {
      Extension fieldExtension = Extension();
      var err = biosealSDK.id3BiosealField_GetFieldExtension(_pHandle.value, fieldExtension.handle);
      if (err == BiosealError.objectDoesNotExist.value) {
        fieldExtension.dispose();
        return null;
      }
      if (err != BiosealError.success.value) {
        fieldExtension.dispose();
        throw BiosealException(err);
      }
      return fieldExtension;
    }