def get_fields(model_class):
return [<EOL>attr for attr, value in model_class.__dict__.items()<EOL>if issubclass(type(value), (mongo.base.BaseField, mongo.EmbeddedDocumentField))  <EOL>]<EOL>
Pass in a mongo model class and extract all the attributes which
are mongoengine fields

Returns:
    list of strings of field attributes