2.0 Preferences object

A preferences object contains a user's preferences for practicing a specific drill.

{
  "style": "MULTIPLE_CHOICE",
  "useIntroductions": true,
  "direction": "PRODUCTIVE",
  "unknownColumns": [ "Plural", "Singular" ]
}

Field	Type	Description
`direction` optional	String	The user's preferred practice direction for this drill: `BIDIRECTIONAL` (default) `PRODUCTIVE` `RECEPTIVE`
`style` optional	String	The user's preferred practice style for this drill: `MULTIPLE_CHOICE` (default) `OPEN_ENDED`
`useIntroductions` optional	Boolean	The user's preference for introductions: `true` (default) `false`
`unknownColumns` optional	List of Strings	The user's preferred unknown column names to include. When omitted or empty, all unknown columns will be included.