public MongoQueryableResource(MongoQueryProvider provider, Expression expression)
 {
     this.provider   = provider;
     this.expression = expression;
 }
 public MongoQueryableResource(MongoMetadata mongoMetadata, string connectionString, string collectionName, Type collectionType)
 {
     this.mongoMetadata = mongoMetadata;
     this.provider      = new MongoQueryProvider(mongoMetadata, connectionString, collectionName, collectionType);
     this.expression    = (new DSPResource[0]).AsQueryable().Expression;
 }