Which code block will produce a DataFrame with the schema containing "customer_id" as LONG type and "predictions" as DOUBLE type, given that:

1. A production model has been logged in MLflow by the data science team
2. The model takes a list of column names as input and outputs a DOUBLE type column
3. The customers table (with customer_id as key column) is already loaded into a DataFrame
4. The required feature columns for the model are properly defined?