reduceKey method
Implementation
String reduceKey(String key) {
var modifiedKey = key.split('.').where((element) {
return element != AppConstants.CONTACT_KEY_PREFIX.toLowerCase() &&
element != AppConstants.CONTACT_KEY_SUFFIX.toLowerCase() &&
element != AppConstants.LIBRARY_NAMESPACE.toLowerCase() &&
element != atClient!.preference!.namespace &&
!atSign.contains(element);
}).join('');
return modifiedKey;
}