IOS-25: Fixed Teacher Model to compatible with some null values
IOS-25: Fixed Teacher Model to compatible with some null values

malaonline/iOS,malaonline/Android,malaonline/Server,malaonline/Server,malaonline/iOS,malaonline/Server,malaonline/Android,malaonline/Server,malaonline/Android,malaonline/iOS